includes/OutputPage.php

   1 <?php
   2 /**
   3  * Preparation for the final page rendering.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 use MediaWiki\Logger\LoggerFactory;
  24 use MediaWiki\Session\SessionManager;
  25 use WrappedString\WrappedString;
  26 use WrappedString\WrappedStringList;
  27
  28 /**
  29  * This class should be covered by a general architecture document which does
  30  * not exist as of January 2011.  This is one of the Core classes and should
  31  * be read at least once by any new developers.
  32  *
  33  * This class is used to prepare the final rendering. A skin is then
  34  * applied to the output parameters (links, javascript, html, categories ...).
  35  *
  36  * @todo FIXME: Another class handles sending the whole page to the client.
  37  *
  38  * Some comments comes from a pairing session between Zak Greant and Antoine Musso
  39  * in November 2010.
  40  *
  41  * @todo document
  42  */
  43 class OutputPage extends ContextSource {
  44         /** @var array Should be private. Used with addMeta() which adds "<meta>" */
  45         protected $mMetatags = [];
  46
  47         /** @var array */
  48         protected $mLinktags = [];
  49
  50         /** @var bool */
  51         protected $mCanonicalUrl = false;
  52
  53         /**
  54          * @var array Additional stylesheets. Looks like this is for extensions.
  55          *   Might be replaced by ResourceLoader.
  56          */
  57         protected $mExtStyles = [];
  58
  59         /**
  60          * @var string Should be private - has getter and setter. Contains
  61          *   the HTML title */
  62         public $mPagetitle = '';
  63
  64         /**
  65          * @var string Contains all of the "<body>" content. Should be private we
  66          *   got set/get accessors and the append() method.
  67          */
  68         public $mBodytext = '';
  69
  70         /** @var string Stores contents of "<title>" tag */
  71         private $mHTMLtitle = '';
  72
  73         /**
  74          * @var bool Is the displayed content related to the source of the
  75          *   corresponding wiki article.
  76          */
  77         private $mIsarticle = false;
  78
  79         /** @var bool Stores "article flag" toggle. */
  80         private $mIsArticleRelated = true;
  81
  82         /**
  83          * @var bool We have to set isPrintable(). Some pages should
  84          * never be printed (ex: redirections).
  85          */
  86         private $mPrintable = false;
  87
  88         /**
  89          * @var array Contains the page subtitle. Special pages usually have some
  90          *   links here. Don't confuse with site subtitle added by skins.
  91          */
  92         private $mSubtitle = [];
  93
  94         /** @var string */
  95         public $mRedirect = '';
  96
  97         /** @var int */
  98         protected $mStatusCode;
  99
 100         /**
 101          * @var string Used for sending cache control.
 102          *   The whole caching system should probably be moved into its own class.
 103          */
 104         protected $mLastModified = '';
 105
 106         /** @var array */
 107         protected $mCategoryLinks = [];
 108
 109         /** @var array */
 110         protected $mCategories = [
 111                 'hidden' => [],
 112                 'normal' => [],
 113         ];
 114
 115         /** @var array */
 116         protected $mIndicators = [];
 117
 118         /** @var array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page') */
 119         private $mLanguageLinks = [];
 120
 121         /**
 122          * Used for JavaScript (predates ResourceLoader)
 123          * @todo We should split JS / CSS.
 124          * mScripts content is inserted as is in "<head>" by Skin. This might
 125          * contain either a link to a stylesheet or inline CSS.
 126          */
 127         private $mScripts = '';
 128
 129         /** @var string Inline CSS styles. Use addInlineStyle() sparingly */
 130         protected $mInlineStyles = '';
 131
 132         /**
 133          * @var string Used by skin template.
 134          * Example: $tpl->set( 'displaytitle', $out->mPageLinkTitle );
 135          */
 136         public $mPageLinkTitle = '';
 137
 138         /** @var array Array of elements in "<head>". Parser might add its own headers! */
 139         protected $mHeadItems = [];
 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 string */
 160         private $rlUserModuleState;
 161
 162         /** @var array */
 163         private $rlExemptStyleModules;
 164
 165         /** @var array */
 166         protected $mJsConfigVars = [];
 167
 168         /** @var array */
 169         protected $mTemplateIds = [];
 170
 171         /** @var array */
 172         protected $mImageTimeKeys = [];
 173
 174         /** @var string */
 175         public $mRedirectCode = '';
 176
 177         protected $mFeedLinksAppendQuery = null;
 178
 179         /** @var array
 180          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 181          * @see ResourceLoaderModule::$origin
 182          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 183          */
 184         protected $mAllowedModules = [
 185                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 186         ];
 187
 188         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 189         protected $mDoNothing = false;
 190
 191         // Parser related.
 192
 193         /** @var int */
 194         protected $mContainsNewMagic = 0;
 195
 196         /**
 197          * lazy initialised, use parserOptions()
 198          * @var ParserOptions
 199          */
 200         protected $mParserOptions = null;
 201
 202         /**
 203          * Handles the Atom / RSS links.
 204          * We probably only support Atom in 2011.
 205          * @see $wgAdvertisedFeedTypes
 206          */
 207         private $mFeedLinks = [];
 208
 209         // Gwicke work on squid caching? Roughly from 2003.
 210         protected $mEnableClientCache = true;
 211
 212         /** @var bool Flag if output should only contain the body of the article. */
 213         private $mArticleBodyOnly = false;
 214
 215         /** @var bool */
 216         protected $mNewSectionLink = false;
 217
 218         /** @var bool */
 219         protected $mHideNewSectionLink = false;
 220
 221         /**
 222          * @var bool Comes from the parser. This was probably made to load CSS/JS
 223          * only if we had "<gallery>". Used directly in CategoryPage.php.
 224          * Looks like ResourceLoader can replace this.
 225          */
 226         public $mNoGallery = false;
 227
 228         /** @var string */
 229         private $mPageTitleActionText = '';
 230
 231         /** @var int Cache stuff. Looks like mEnableClientCache */
 232         protected $mCdnMaxage = 0;
 233         /** @var int Upper limit on mCdnMaxage */
 234         protected $mCdnMaxageLimit = INF;
 235
 236         /**
 237          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 238          * be sent. This should be done for pages where edit actions are possible.
 239          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 240          */
 241         protected $mPreventClickjacking = true;
 242
 243         /** @var int To include the variable {{REVISIONID}} */
 244         private $mRevisionId = null;
 245
 246         /** @var string */
 247         private $mRevisionTimestamp = null;
 248
 249         /** @var array */
 250         protected $mFileVersion = null;
 251
 252         /**
 253          * @var array An array of stylesheet filenames (relative from skins path),
 254          * with options for CSS media, IE conditions, and RTL/LTR direction.
 255          * For internal use; add settings in the skin via $this->addStyle()
 256          *
 257          * Style again! This seems like a code duplication since we already have
 258          * mStyles. This is what makes Open Source amazing.
 259          */
 260         protected $styles = [];
 261
 262         private $mIndexPolicy = 'index';
 263         private $mFollowPolicy = 'follow';
 264         private $mVaryHeader = [
 265                 'Accept-Encoding' => [ 'match=gzip' ],
 266         ];
 267
 268         /**
 269          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 270          * of the redirect.
 271          *
 272          * @var Title
 273          */
 274         private $mRedirectedFrom = null;
 275
 276         /**
 277          * Additional key => value data
 278          */
 279         private $mProperties = [];
 280
 281         /**
 282          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 283          */
 284         private $mTarget = null;
 285
 286         /**
 287          * @var bool Whether parser output should contain table of contents
 288          */
 289         private $mEnableTOC = true;
 290
 291         /**
 292          * @var bool Whether parser output should contain section edit links
 293          */
 294         private $mEnableSectionEditLinks = true;
 295
 296         /**
 297          * @var string|null The URL to send in a <link> element with rel=copyright
 298          */
 299         private $copyrightUrl;
 300
 301         /**
 302          * Constructor for OutputPage. This should not be called directly.
 303          * Instead a new RequestContext should be created and it will implicitly create
 304          * a OutputPage tied to that context.
 305          * @param IContextSource|null $context
 306          */
 307         function __construct( IContextSource $context = null ) {
 308                 if ( $context === null ) {
 309                         # Extensions should use `new RequestContext` instead of `new OutputPage` now.
 310                         wfDeprecated( __METHOD__, '1.18' );
 311                 } else {
 312                         $this->setContext( $context );
 313                 }
 314         }
 315
 316         /**
 317          * Redirect to $url rather than displaying the normal page
 318          *
 319          * @param string $url URL
 320          * @param string $responsecode HTTP status code
 321          */
 322         public function redirect( $url, $responsecode = '302' ) {
 323                 # Strip newlines as a paranoia check for header injection in PHP<5.1.2
 324                 $this->mRedirect = str_replace( "\n", '', $url );
 325                 $this->mRedirectCode = $responsecode;
 326         }
 327
 328         /**
 329          * Get the URL to redirect to, or an empty string if not redirect URL set
 330          *
 331          * @return string
 332          */
 333         public function getRedirect() {
 334                 return $this->mRedirect;
 335         }
 336
 337         /**
 338          * Set the copyright URL to send with the output.
 339          * Empty string to omit, null to reset.
 340          *
 341          * @since 1.26
 342          *
 343          * @param string|null $url
 344          */
 345         public function setCopyrightUrl( $url ) {
 346                 $this->copyrightUrl = $url;
 347         }
 348
 349         /**
 350          * Set the HTTP status code to send with the output.
 351          *
 352          * @param int $statusCode
 353          */
 354         public function setStatusCode( $statusCode ) {
 355                 $this->mStatusCode = $statusCode;
 356         }
 357
 358         /**
 359          * Add a new "<meta>" tag
 360          * To add an http-equiv meta tag, precede the name with "http:"
 361          *
 362          * @param string $name Tag name
 363          * @param string $val Tag value
 364          */
 365         function addMeta( $name, $val ) {
 366                 array_push( $this->mMetatags, [ $name, $val ] );
 367         }
 368
 369         /**
 370          * Returns the current <meta> tags
 371          *
 372          * @since 1.25
 373          * @return array
 374          */
 375         public function getMetaTags() {
 376                 return $this->mMetatags;
 377         }
 378
 379         /**
 380          * Add a new \<link\> tag to the page header.
 381          *
 382          * Note: use setCanonicalUrl() for rel=canonical.
 383          *
 384          * @param array $linkarr Associative array of attributes.
 385          */
 386         function addLink( array $linkarr ) {
 387                 array_push( $this->mLinktags, $linkarr );
 388         }
 389
 390         /**
 391          * Returns the current <link> tags
 392          *
 393          * @since 1.25
 394          * @return array
 395          */
 396         public function getLinkTags() {
 397                 return $this->mLinktags;
 398         }
 399
 400         /**
 401          * Add a new \<link\> with "rel" attribute set to "meta"
 402          *
 403          * @param array $linkarr Associative array mapping attribute names to their
 404          *                 values, both keys and values will be escaped, and the
 405          *                 "rel" attribute will be automatically added
 406          */
 407         function addMetadataLink( array $linkarr ) {
 408                 $linkarr['rel'] = $this->getMetadataAttribute();
 409                 $this->addLink( $linkarr );
 410         }
 411
 412         /**
 413          * Set the URL to be used for the <link rel=canonical>. This should be used
 414          * in preference to addLink(), to avoid duplicate link tags.
 415          * @param string $url
 416          */
 417         function setCanonicalUrl( $url ) {
 418                 $this->mCanonicalUrl = $url;
 419         }
 420
 421         /**
 422          * Returns the URL to be used for the <link rel=canonical> if
 423          * one is set.
 424          *
 425          * @since 1.25
 426          * @return bool|string
 427          */
 428         public function getCanonicalUrl() {
 429                 return $this->mCanonicalUrl;
 430         }
 431
 432         /**
 433          * Get the value of the "rel" attribute for metadata links
 434          *
 435          * @return string
 436          */
 437         public function getMetadataAttribute() {
 438                 # note: buggy CC software only reads first "meta" link
 439                 static $haveMeta = false;
 440                 if ( $haveMeta ) {
 441                         return 'alternate meta';
 442                 } else {
 443                         $haveMeta = true;
 444                         return 'meta';
 445                 }
 446         }
 447
 448         /**
 449          * Add raw HTML to the list of scripts (including \<script\> tag, etc.)
 450          * Internal use only. Use OutputPage::addModules() or OutputPage::addJsConfigVars()
 451          * if possible.
 452          *
 453          * @param string $script Raw HTML
 454          */
 455         function addScript( $script ) {
 456                 $this->mScripts .= $script;
 457         }
 458
 459         /**
 460          * Register and add a stylesheet from an extension directory.
 461          *
 462          * @deprecated since 1.27 use addModuleStyles() or addStyle() instead
 463          * @param string $url Path to sheet.  Provide either a full url (beginning
 464          *             with 'http', etc) or a relative path from the document root
 465          *             (beginning with '/').  Otherwise it behaves identically to
 466          *             addStyle() and draws from the /skins folder.
 467          */
 468         public function addExtensionStyle( $url ) {
 469                 wfDeprecated( __METHOD__, '1.27' );
 470                 array_push( $this->mExtStyles, $url );
 471         }
 472
 473         /**
 474          * Get all styles added by extensions
 475          *
 476          * @deprecated since 1.27
 477          * @return array
 478          */
 479         function getExtStyle() {
 480                 wfDeprecated( __METHOD__, '1.27' );
 481                 return $this->mExtStyles;
 482         }
 483
 484         /**
 485          * Add a JavaScript file out of skins/common, or a given relative path.
 486          * Internal use only. Use OutputPage::addModules() if possible.
 487          *
 488          * @param string $file Filename in skins/common or complete on-server path
 489          *              (/foo/bar.js)
 490          * @param string $version Style version of the file. Defaults to $wgStyleVersion
 491          */
 492         public function addScriptFile( $file, $version = null ) {
 493                 // See if $file parameter is an absolute URL or begins with a slash
 494                 if ( substr( $file, 0, 1 ) == '/' || preg_match( '#^[a-z]*://#i', $file ) ) {
 495                         $path = $file;
 496                 } else {
 497                         $path = $this->getConfig()->get( 'StylePath' ) . "/common/{$file}";
 498                 }
 499                 if ( is_null( $version ) ) {
 500                         $version = $this->getConfig()->get( 'StyleVersion' );
 501                 }
 502                 $this->addScript( Html::linkedScript( wfAppendQuery( $path, $version ) ) );
 503         }
 504
 505         /**
 506          * Add a self-contained script tag with the given contents
 507          * Internal use only. Use OutputPage::addModules() if possible.
 508          *
 509          * @param string $script JavaScript text, no script tags
 510          */
 511         public function addInlineScript( $script ) {
 512                 $this->mScripts .= Html::inlineScript( $script );
 513         }
 514
 515         /**
 516          * Filter an array of modules to remove insufficiently trustworthy members, and modules
 517          * which are no longer registered (eg a page is cached before an extension is disabled)
 518          * @param array $modules
 519          * @param string|null $position If not null, only return modules with this position
 520          * @param string $type
 521          * @return array
 522          */
 523         protected function filterModules( array $modules, $position = null,
 524                 $type = ResourceLoaderModule::TYPE_COMBINED
 525         ) {
 526                 $resourceLoader = $this->getResourceLoader();
 527                 $filteredModules = [];
 528                 foreach ( $modules as $val ) {
 529                         $module = $resourceLoader->getModule( $val );
 530                         if ( $module instanceof ResourceLoaderModule
 531                                 && $module->getOrigin() <= $this->getAllowedModules( $type )
 532                                 && ( is_null( $position ) || $module->getPosition() == $position )
 533                                 && ( !$this->mTarget || in_array( $this->mTarget, $module->getTargets() ) )
 534                         ) {
 535                                 $filteredModules[] = $val;
 536                         }
 537                 }
 538                 return $filteredModules;
 539         }
 540
 541         /**
 542          * Get the list of modules to include on this page
 543          *
 544          * @param bool $filter Whether to filter out insufficiently trustworthy modules
 545          * @param string|null $position If not null, only return modules with this position
 546          * @param string $param
 547          * @return array Array of module names
 548          */
 549         public function getModules( $filter = false, $position = null, $param = 'mModules',
 550                 $type = ResourceLoaderModule::TYPE_COMBINED
 551         ) {
 552                 $modules = array_values( array_unique( $this->$param ) );
 553                 return $filter
 554                         ? $this->filterModules( $modules, $position, $type )
 555                         : $modules;
 556         }
 557
 558         /**
 559          * Add one or more modules recognized by ResourceLoader. Modules added
 560          * through this function will be loaded by ResourceLoader when the
 561          * page loads.
 562          *
 563          * @param string|array $modules Module name (string) or array of module names
 564          */
 565         public function addModules( $modules ) {
 566                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 567         }
 568
 569         /**
 570          * Get the list of module JS to include on this page
 571          *
 572          * @param bool $filter
 573          * @param string|null $position
 574          * @return array Array of module names
 575          */
 576         public function getModuleScripts( $filter = false, $position = null ) {
 577                 return $this->getModules( $filter, $position, 'mModuleScripts',
 578                         ResourceLoaderModule::TYPE_SCRIPTS
 579                 );
 580         }
 581
 582         /**
 583          * Add only JS of one or more modules recognized by ResourceLoader. Module
 584          * scripts added through this function will be loaded by ResourceLoader when
 585          * the page loads.
 586          *
 587          * @param string|array $modules Module name (string) or array of module names
 588          */
 589         public function addModuleScripts( $modules ) {
 590                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 591         }
 592
 593         /**
 594          * Get the list of module CSS to include on this page
 595          *
 596          * @param bool $filter
 597          * @param string|null $position
 598          * @return array Array of module names
 599          */
 600         public function getModuleStyles( $filter = false, $position = null ) {
 601                 return $this->getModules( $filter, $position, 'mModuleStyles',
 602                         ResourceLoaderModule::TYPE_STYLES
 603                 );
 604         }
 605
 606         /**
 607          * Add only CSS of one or more modules recognized by ResourceLoader.
 608          *
 609          * Module styles added through this function will be added using standard link CSS
 610          * tags, rather than as a combined Javascript and CSS package. Thus, they will
 611          * load when JavaScript is disabled (unless CSS also happens to be disabled).
 612          *
 613          * @param string|array $modules Module name (string) or array of module names
 614          */
 615         public function addModuleStyles( $modules ) {
 616                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 617         }
 618
 619         /**
 620          * @return null|string ResourceLoader target
 621          */
 622         public function getTarget() {
 623                 return $this->mTarget;
 624         }
 625
 626         /**
 627          * Sets ResourceLoader target for load.php links. If null, will be omitted
 628          *
 629          * @param string|null $target
 630          */
 631         public function setTarget( $target ) {
 632                 $this->mTarget = $target;
 633         }
 634
 635         /**
 636          * Get an array of head items
 637          *
 638          * @return array
 639          */
 640         function getHeadItemsArray() {
 641                 return $this->mHeadItems;
 642         }
 643
 644         /**
 645          * Add or replace a head item to the output
 646          *
 647          * Whenever possible, use more specific options like ResourceLoader modules,
 648          * OutputPage::addLink(), OutputPage::addMetaLink() and OutputPage::addFeedLink()
 649          * Fallback options for those are: OutputPage::addStyle, OutputPage::addScript(),
 650          * OutputPage::addInlineScript() and OutputPage::addInlineStyle()
 651          * This would be your very LAST fallback.
 652          *
 653          * @param string $name Item name
 654          * @param string $value Raw HTML
 655          */
 656         public function addHeadItem( $name, $value ) {
 657                 $this->mHeadItems[$name] = $value;
 658         }
 659
 660         /**
 661          * Add one or more head items to the output
 662          *
 663          * @since 1.28
 664          * @param string|string[] $value Raw HTML
 665          */
 666         public function addHeadItems( $values ) {
 667                 $this->mHeadItems = array_merge( $this->mHeadItems, (array)$values );
 668         }
 669
 670         /**
 671          * Check if the header item $name is already set
 672          *
 673          * @param string $name Item name
 674          * @return bool
 675          */
 676         public function hasHeadItem( $name ) {
 677                 return isset( $this->mHeadItems[$name] );
 678         }
 679
 680         /**
 681          * @deprecated since 1.28 Obsolete - wgUseETag experiment was removed.
 682          * @param string $tag
 683          */
 684         public function setETag( $tag ) {
 685         }
 686
 687         /**
 688          * Set whether the output should only contain the body of the article,
 689          * without any skin, sidebar, etc.
 690          * Used e.g. when calling with "action=render".
 691          *
 692          * @param bool $only Whether to output only the body of the article
 693          */
 694         public function setArticleBodyOnly( $only ) {
 695                 $this->mArticleBodyOnly = $only;
 696         }
 697
 698         /**
 699          * Return whether the output will contain only the body of the article
 700          *
 701          * @return bool
 702          */
 703         public function getArticleBodyOnly() {
 704                 return $this->mArticleBodyOnly;
 705         }
 706
 707         /**
 708          * Set an additional output property
 709          * @since 1.21
 710          *
 711          * @param string $name
 712          * @param mixed $value
 713          */
 714         public function setProperty( $name, $value ) {
 715                 $this->mProperties[$name] = $value;
 716         }
 717
 718         /**
 719          * Get an additional output property
 720          * @since 1.21
 721          *
 722          * @param string $name
 723          * @return mixed Property value or null if not found
 724          */
 725         public function getProperty( $name ) {
 726                 if ( isset( $this->mProperties[$name] ) ) {
 727                         return $this->mProperties[$name];
 728                 } else {
 729                         return null;
 730                 }
 731         }
 732
 733         /**
 734          * checkLastModified tells the client to use the client-cached page if
 735          * possible. If successful, the OutputPage is disabled so that
 736          * any future call to OutputPage->output() have no effect.
 737          *
 738          * Side effect: sets mLastModified for Last-Modified header
 739          *
 740          * @param string $timestamp
 741          *
 742          * @return bool True if cache-ok headers was sent.
 743          */
 744         public function checkLastModified( $timestamp ) {
 745                 if ( !$timestamp || $timestamp == '19700101000000' ) {
 746                         wfDebug( __METHOD__ . ": CACHE DISABLED, NO TIMESTAMP\n" );
 747                         return false;
 748                 }
 749                 $config = $this->getConfig();
 750                 if ( !$config->get( 'CachePages' ) ) {
 751                         wfDebug( __METHOD__ . ": CACHE DISABLED\n" );
 752                         return false;
 753                 }
 754
 755                 $timestamp = wfTimestamp( TS_MW, $timestamp );
 756                 $modifiedTimes = [
 757                         'page' => $timestamp,
 758                         'user' => $this->getUser()->getTouched(),
 759                         'epoch' => $config->get( 'CacheEpoch' )
 760                 ];
 761                 if ( $config->get( 'UseSquid' ) ) {
 762                         // bug 44570: the core page itself may not change, but resources might
 763                         $modifiedTimes['sepoch'] = wfTimestamp( TS_MW, time() - $config->get( 'SquidMaxage' ) );
 764                 }
 765                 Hooks::run( 'OutputPageCheckLastModified', [ &$modifiedTimes, $this ] );
 766
 767                 $maxModified = max( $modifiedTimes );
 768                 $this->mLastModified = wfTimestamp( TS_RFC2822, $maxModified );
 769
 770                 $clientHeader = $this->getRequest()->getHeader( 'If-Modified-Since' );
 771                 if ( $clientHeader === false ) {
 772                         wfDebug( __METHOD__ . ": client did not send If-Modified-Since header", 'private' );
 773                         return false;
 774                 }
 775
 776                 # IE sends sizes after the date like this:
 777                 # Wed, 20 Aug 2003 06:51:19 GMT; length=5202
 778                 # this breaks strtotime().
 779                 $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 780
 781                 MediaWiki\suppressWarnings(); // E_STRICT system time bitching
 782                 $clientHeaderTime = strtotime( $clientHeader );
 783                 MediaWiki\restoreWarnings();
 784                 if ( !$clientHeaderTime ) {
 785                         wfDebug( __METHOD__
 786                                 . ": unable to parse the client's If-Modified-Since header: $clientHeader\n" );
 787                         return false;
 788                 }
 789                 $clientHeaderTime = wfTimestamp( TS_MW, $clientHeaderTime );
 790
 791                 # Make debug info
 792                 $info = '';
 793                 foreach ( $modifiedTimes as $name => $value ) {
 794                         if ( $info !== '' ) {
 795                                 $info .= ', ';
 796                         }
 797                         $info .= "$name=" . wfTimestamp( TS_ISO_8601, $value );
 798                 }
 799
 800                 wfDebug( __METHOD__ . ": client sent If-Modified-Since: " .
 801                         wfTimestamp( TS_ISO_8601, $clientHeaderTime ), 'private' );
 802                 wfDebug( __METHOD__ . ": effective Last-Modified: " .
 803                         wfTimestamp( TS_ISO_8601, $maxModified ), 'private' );
 804                 if ( $clientHeaderTime < $maxModified ) {
 805                         wfDebug( __METHOD__ . ": STALE, $info", 'private' );
 806                         return false;
 807                 }
 808
 809                 # Not modified
 810                 # Give a 304 Not Modified response code and disable body output
 811                 wfDebug( __METHOD__ . ": NOT MODIFIED, $info", 'private' );
 812                 ini_set( 'zlib.output_compression', 0 );
 813                 $this->getRequest()->response()->statusHeader( 304 );
 814                 $this->sendCacheControl();
 815                 $this->disable();
 816
 817                 // Don't output a compressed blob when using ob_gzhandler;
 818                 // it's technically against HTTP spec and seems to confuse
 819                 // Firefox when the response gets split over two packets.
 820                 wfClearOutputBuffers();
 821
 822                 return true;
 823         }
 824
 825         /**
 826          * Override the last modified timestamp
 827          *
 828          * @param string $timestamp New timestamp, in a format readable by
 829          *        wfTimestamp()
 830          */
 831         public function setLastModified( $timestamp ) {
 832                 $this->mLastModified = wfTimestamp( TS_RFC2822, $timestamp );
 833         }
 834
 835         /**
 836          * Set the robot policy for the page: <http://www.robotstxt.org/meta.html>
 837          *
 838          * @param string $policy The literal string to output as the contents of
 839          *   the meta tag.  Will be parsed according to the spec and output in
 840          *   standardized form.
 841          * @return null
 842          */
 843         public function setRobotPolicy( $policy ) {
 844                 $policy = Article::formatRobotPolicy( $policy );
 845
 846                 if ( isset( $policy['index'] ) ) {
 847                         $this->setIndexPolicy( $policy['index'] );
 848                 }
 849                 if ( isset( $policy['follow'] ) ) {
 850                         $this->setFollowPolicy( $policy['follow'] );
 851                 }
 852         }
 853
 854         /**
 855          * Set the index policy for the page, but leave the follow policy un-
 856          * touched.
 857          *
 858          * @param string $policy Either 'index' or 'noindex'.
 859          * @return null
 860          */
 861         public function setIndexPolicy( $policy ) {
 862                 $policy = trim( $policy );
 863                 if ( in_array( $policy, [ 'index', 'noindex' ] ) ) {
 864                         $this->mIndexPolicy = $policy;
 865                 }
 866         }
 867
 868         /**
 869          * Set the follow policy for the page, but leave the index policy un-
 870          * touched.
 871          *
 872          * @param string $policy Either 'follow' or 'nofollow'.
 873          * @return null
 874          */
 875         public function setFollowPolicy( $policy ) {
 876                 $policy = trim( $policy );
 877                 if ( in_array( $policy, [ 'follow', 'nofollow' ] ) ) {
 878                         $this->mFollowPolicy = $policy;
 879                 }
 880         }
 881
 882         /**
 883          * Set the new value of the "action text", this will be added to the
 884          * "HTML title", separated from it with " - ".
 885          *
 886          * @param string $text New value of the "action text"
 887          */
 888         public function setPageTitleActionText( $text ) {
 889                 $this->mPageTitleActionText = $text;
 890         }
 891
 892         /**
 893          * Get the value of the "action text"
 894          *
 895          * @return string
 896          */
 897         public function getPageTitleActionText() {
 898                 return $this->mPageTitleActionText;
 899         }
 900
 901         /**
 902          * "HTML title" means the contents of "<title>".
 903          * It is stored as plain, unescaped text and will be run through htmlspecialchars in the skin file.
 904          *
 905          * @param string|Message $name
 906          */
 907         public function setHTMLTitle( $name ) {
 908                 if ( $name instanceof Message ) {
 909                         $this->mHTMLtitle = $name->setContext( $this->getContext() )->text();
 910                 } else {
 911                         $this->mHTMLtitle = $name;
 912                 }
 913         }
 914
 915         /**
 916          * Return the "HTML title", i.e. the content of the "<title>" tag.
 917          *
 918          * @return string
 919          */
 920         public function getHTMLTitle() {
 921                 return $this->mHTMLtitle;
 922         }
 923
 924         /**
 925          * Set $mRedirectedFrom, the Title of the page which redirected us to the current page.
 926          *
 927          * @param Title $t
 928          */
 929         public function setRedirectedFrom( $t ) {
 930                 $this->mRedirectedFrom = $t;
 931         }
 932
 933         /**
 934          * "Page title" means the contents of \<h1\>. It is stored as a valid HTML
 935          * fragment. This function allows good tags like \<sup\> in the \<h1\> tag,
 936          * but not bad tags like \<script\>. This function automatically sets
 937          * \<title\> to the same content as \<h1\> but with all tags removed. Bad
 938          * tags that were escaped in \<h1\> will still be escaped in \<title\>, and
 939          * good tags like \<i\> will be dropped entirely.
 940          *
 941          * @param string|Message $name
 942          */
 943         public function setPageTitle( $name ) {
 944                 if ( $name instanceof Message ) {
 945                         $name = $name->setContext( $this->getContext() )->text();
 946                 }
 947
 948                 # change "<script>foo&bar</script>" to "&lt;script&gt;foo&amp;bar&lt;/script&gt;"
 949                 # but leave "<i>foobar</i>" alone
 950                 $nameWithTags = Sanitizer::normalizeCharReferences( Sanitizer::removeHTMLtags( $name ) );
 951                 $this->mPagetitle = $nameWithTags;
 952
 953                 # change "<i>foo&amp;bar</i>" to "foo&bar"
 954                 $this->setHTMLTitle(
 955                         $this->msg( 'pagetitle' )->rawParams( Sanitizer::stripAllTags( $nameWithTags ) )
 956                                 ->inContentLanguage()
 957                 );
 958         }
 959
 960         /**
 961          * Return the "page title", i.e. the content of the \<h1\> tag.
 962          *
 963          * @return string
 964          */
 965         public function getPageTitle() {
 966                 return $this->mPagetitle;
 967         }
 968
 969         /**
 970          * Set the Title object to use
 971          *
 972          * @param Title $t
 973          */
 974         public function setTitle( Title $t ) {
 975                 $this->getContext()->setTitle( $t );
 976         }
 977
 978         /**
 979          * Replace the subtitle with $str
 980          *
 981          * @param string|Message $str New value of the subtitle. String should be safe HTML.
 982          */
 983         public function setSubtitle( $str ) {
 984                 $this->clearSubtitle();
 985                 $this->addSubtitle( $str );
 986         }
 987
 988         /**
 989          * Add $str to the subtitle
 990          *
 991          * @param string|Message $str String or Message to add to the subtitle. String should be safe HTML.
 992          */
 993         public function addSubtitle( $str ) {
 994                 if ( $str instanceof Message ) {
 995                         $this->mSubtitle[] = $str->setContext( $this->getContext() )->parse();
 996                 } else {
 997                         $this->mSubtitle[] = $str;
 998                 }
 999         }
1000
1001         /**
1002          * Build message object for a subtitle containing a backlink to a page
1003          *
1004          * @param Title $title Title to link to
1005          * @param array $query Array of additional parameters to include in the link
1006          * @return Message
1007          * @since 1.25
1008          */
1009         public static function buildBacklinkSubtitle( Title $title, $query = [] ) {
1010                 if ( $title->isRedirect() ) {
1011                         $query['redirect'] = 'no';
1012                 }
1013                 return wfMessage( 'backlinksubtitle' )
1014                         ->rawParams( Linker::link( $title, null, [], $query ) );
1015         }
1016
1017         /**
1018          * Add a subtitle containing a backlink to a page
1019          *
1020          * @param Title $title Title to link to
1021          * @param array $query Array of additional parameters to include in the link
1022          */
1023         public function addBacklinkSubtitle( Title $title, $query = [] ) {
1024                 $this->addSubtitle( self::buildBacklinkSubtitle( $title, $query ) );
1025         }
1026
1027         /**
1028          * Clear the subtitles
1029          */
1030         public function clearSubtitle() {
1031                 $this->mSubtitle = [];
1032         }
1033
1034         /**
1035          * Get the subtitle
1036          *
1037          * @return string
1038          */
1039         public function getSubtitle() {
1040                 return implode( "<br />\n\t\t\t\t", $this->mSubtitle );
1041         }
1042
1043         /**
1044          * Set the page as printable, i.e. it'll be displayed with all
1045          * print styles included
1046          */
1047         public function setPrintable() {
1048                 $this->mPrintable = true;
1049         }
1050
1051         /**
1052          * Return whether the page is "printable"
1053          *
1054          * @return bool
1055          */
1056         public function isPrintable() {
1057                 return $this->mPrintable;
1058         }
1059
1060         /**
1061          * Disable output completely, i.e. calling output() will have no effect
1062          */
1063         public function disable() {
1064                 $this->mDoNothing = true;
1065         }
1066
1067         /**
1068          * Return whether the output will be completely disabled
1069          *
1070          * @return bool
1071          */
1072         public function isDisabled() {
1073                 return $this->mDoNothing;
1074         }
1075
1076         /**
1077          * Show an "add new section" link?
1078          *
1079          * @return bool
1080          */
1081         public function showNewSectionLink() {
1082                 return $this->mNewSectionLink;
1083         }
1084
1085         /**
1086          * Forcibly hide the new section link?
1087          *
1088          * @return bool
1089          */
1090         public function forceHideNewSectionLink() {
1091                 return $this->mHideNewSectionLink;
1092         }
1093
1094         /**
1095          * Add or remove feed links in the page header
1096          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1097          * for the new version
1098          * @see addFeedLink()
1099          *
1100          * @param bool $show True: add default feeds, false: remove all feeds
1101          */
1102         public function setSyndicated( $show = true ) {
1103                 if ( $show ) {
1104                         $this->setFeedAppendQuery( false );
1105                 } else {
1106                         $this->mFeedLinks = [];
1107                 }
1108         }
1109
1110         /**
1111          * Add default feeds to the page header
1112          * This is mainly kept for backward compatibility, see OutputPage::addFeedLink()
1113          * for the new version
1114          * @see addFeedLink()
1115          *
1116          * @param string $val Query to append to feed links or false to output
1117          *        default links
1118          */
1119         public function setFeedAppendQuery( $val ) {
1120                 $this->mFeedLinks = [];
1121
1122                 foreach ( $this->getConfig()->get( 'AdvertisedFeedTypes' ) as $type ) {
1123                         $query = "feed=$type";
1124                         if ( is_string( $val ) ) {
1125                                 $query .= '&' . $val;
1126                         }
1127                         $this->mFeedLinks[$type] = $this->getTitle()->getLocalURL( $query );
1128                 }
1129         }
1130
1131         /**
1132          * Add a feed link to the page header
1133          *
1134          * @param string $format Feed type, should be a key of $wgFeedClasses
1135          * @param string $href URL
1136          */
1137         public function addFeedLink( $format, $href ) {
1138                 if ( in_array( $format, $this->getConfig()->get( 'AdvertisedFeedTypes' ) ) ) {
1139                         $this->mFeedLinks[$format] = $href;
1140                 }
1141         }
1142
1143         /**
1144          * Should we output feed links for this page?
1145          * @return bool
1146          */
1147         public function isSyndicated() {
1148                 return count( $this->mFeedLinks ) > 0;
1149         }
1150
1151         /**
1152          * Return URLs for each supported syndication format for this page.
1153          * @return array Associating format keys with URLs
1154          */
1155         public function getSyndicationLinks() {
1156                 return $this->mFeedLinks;
1157         }
1158
1159         /**
1160          * Will currently always return null
1161          *
1162          * @return null
1163          */
1164         public function getFeedAppendQuery() {
1165                 return $this->mFeedLinksAppendQuery;
1166         }
1167
1168         /**
1169          * Set whether the displayed content is related to the source of the
1170          * corresponding article on the wiki
1171          * Setting true will cause the change "article related" toggle to true
1172          *
1173          * @param bool $v
1174          */
1175         public function setArticleFlag( $v ) {
1176                 $this->mIsarticle = $v;
1177                 if ( $v ) {
1178                         $this->mIsArticleRelated = $v;
1179                 }
1180         }
1181
1182         /**
1183          * Return whether the content displayed page is related to the source of
1184          * the corresponding article on the wiki
1185          *
1186          * @return bool
1187          */
1188         public function isArticle() {
1189                 return $this->mIsarticle;
1190         }
1191
1192         /**
1193          * Set whether this page is related an article on the wiki
1194          * Setting false will cause the change of "article flag" toggle to false
1195          *
1196          * @param bool $v
1197          */
1198         public function setArticleRelated( $v ) {
1199                 $this->mIsArticleRelated = $v;
1200                 if ( !$v ) {
1201                         $this->mIsarticle = false;
1202                 }
1203         }
1204
1205         /**
1206          * Return whether this page is related an article on the wiki
1207          *
1208          * @return bool
1209          */
1210         public function isArticleRelated() {
1211                 return $this->mIsArticleRelated;
1212         }
1213
1214         /**
1215          * Add new language links
1216          *
1217          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1218          *                               (e.g. 'fr:Test page')
1219          */
1220         public function addLanguageLinks( array $newLinkArray ) {
1221                 $this->mLanguageLinks += $newLinkArray;
1222         }
1223
1224         /**
1225          * Reset the language links and add new language links
1226          *
1227          * @param string[] $newLinkArray Array of interwiki-prefixed (non DB key) titles
1228          *                               (e.g. 'fr:Test page')
1229          */
1230         public function setLanguageLinks( array $newLinkArray ) {
1231                 $this->mLanguageLinks = $newLinkArray;
1232         }
1233
1234         /**
1235          * Get the list of language links
1236          *
1237          * @return string[] Array of interwiki-prefixed (non DB key) titles (e.g. 'fr:Test page')
1238          */
1239         public function getLanguageLinks() {
1240                 return $this->mLanguageLinks;
1241         }
1242
1243         /**
1244          * Add an array of categories, with names in the keys
1245          *
1246          * @param array $categories Mapping category name => sort key
1247          */
1248         public function addCategoryLinks( array $categories ) {
1249                 global $wgContLang;
1250
1251                 if ( !is_array( $categories ) || count( $categories ) == 0 ) {
1252                         return;
1253                 }
1254
1255                 $res = $this->addCategoryLinksToLBAndGetResult( $categories );
1256
1257                 # Set all the values to 'normal'.
1258                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1259
1260                 # Mark hidden categories
1261                 foreach ( $res as $row ) {
1262                         if ( isset( $row->pp_value ) ) {
1263                                 $categories[$row->page_title] = 'hidden';
1264                         }
1265                 }
1266
1267                 # Add the remaining categories to the skin
1268                 if ( Hooks::run(
1269                         'OutputPageMakeCategoryLinks',
1270                         [ &$this, $categories, &$this->mCategoryLinks ] )
1271                 ) {
1272                         foreach ( $categories as $category => $type ) {
1273                                 // array keys will cast numeric category names to ints, so cast back to string
1274                                 $category = (string)$category;
1275                                 $origcategory = $category;
1276                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1277                                 if ( !$title ) {
1278                                         continue;
1279                                 }
1280                                 $wgContLang->findVariantLink( $category, $title, true );
1281                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1282                                         continue;
1283                                 }
1284                                 $text = $wgContLang->convertHtml( $title->getText() );
1285                                 $this->mCategories[$type][] = $title->getText();
1286                                 $this->mCategoryLinks[$type][] = Linker::link( $title, $text );
1287                         }
1288                 }
1289         }
1290
1291         /**
1292          * @param array $categories
1293          * @return bool|ResultWrapper
1294          */
1295         protected function addCategoryLinksToLBAndGetResult( array $categories ) {
1296                 # Add the links to a LinkBatch
1297                 $arr = [ NS_CATEGORY => $categories ];
1298                 $lb = new LinkBatch;
1299                 $lb->setArray( $arr );
1300
1301                 # Fetch existence plus the hiddencat property
1302                 $dbr = wfGetDB( DB_REPLICA );
1303                 $fields = array_merge(
1304                         LinkCache::getSelectFields(),
1305                         [ 'page_namespace', 'page_title', 'pp_value' ]
1306                 );
1307
1308                 $res = $dbr->select( [ 'page', 'page_props' ],
1309                         $fields,
1310                         $lb->constructSet( 'page', $dbr ),
1311                         __METHOD__,
1312                         [],
1313                         [ 'page_props' => [ 'LEFT JOIN', [
1314                                 'pp_propname' => 'hiddencat',
1315                                 'pp_page = page_id'
1316                         ] ] ]
1317                 );
1318
1319                 # Add the results to the link cache
1320                 $lb->addResultToCache( LinkCache::singleton(), $res );
1321
1322                 return $res;
1323         }
1324
1325         /**
1326          * Reset the category links (but not the category list) and add $categories
1327          *
1328          * @param array $categories Mapping category name => sort key
1329          */
1330         public function setCategoryLinks( array $categories ) {
1331                 $this->mCategoryLinks = [];
1332                 $this->addCategoryLinks( $categories );
1333         }
1334
1335         /**
1336          * Get the list of category links, in a 2-D array with the following format:
1337          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1338          * hidden categories) and $link a HTML fragment with a link to the category
1339          * page
1340          *
1341          * @return array
1342          */
1343         public function getCategoryLinks() {
1344                 return $this->mCategoryLinks;
1345         }
1346
1347         /**
1348          * Get the list of category names this page belongs to.
1349          *
1350          * @param string $type The type of categories which should be returned. Possible values:
1351          *  * all: all categories of all types
1352          *  * hidden: only the hidden categories
1353          *  * normal: all categories, except hidden categories
1354          * @return array Array of strings
1355          */
1356         public function getCategories( $type = 'all' ) {
1357                 if ( $type === 'all' ) {
1358                         $allCategories = [];
1359                         foreach ( $this->mCategories as $categories ) {
1360                                 $allCategories = array_merge( $allCategories, $categories );
1361                         }
1362                         return $allCategories;
1363                 }
1364                 if ( !isset( $this->mCategories[$type] ) ) {
1365                         throw new InvalidArgumentException( 'Invalid category type given: ' . $type );
1366                 }
1367                 return $this->mCategories[$type];
1368         }
1369
1370         /**
1371          * Add an array of indicators, with their identifiers as array
1372          * keys and HTML contents as values.
1373          *
1374          * In case of duplicate keys, existing values are overwritten.
1375          *
1376          * @param array $indicators
1377          * @since 1.25
1378          */
1379         public function setIndicators( array $indicators ) {
1380                 $this->mIndicators = $indicators + $this->mIndicators;
1381                 // Keep ordered by key
1382                 ksort( $this->mIndicators );
1383         }
1384
1385         /**
1386          * Get the indicators associated with this page.
1387          *
1388          * The array will be internally ordered by item keys.
1389          *
1390          * @return array Keys: identifiers, values: HTML contents
1391          * @since 1.25
1392          */
1393         public function getIndicators() {
1394                 return $this->mIndicators;
1395         }
1396
1397         /**
1398          * Adds help link with an icon via page indicators.
1399          * Link target can be overridden by a local message containing a wikilink:
1400          * the message key is: lowercase action or special page name + '-helppage'.
1401          * @param string $to Target MediaWiki.org page title or encoded URL.
1402          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1403          * @since 1.25
1404          */
1405         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1406                 $this->addModuleStyles( 'mediawiki.helplink' );
1407                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1408
1409                 if ( $overrideBaseUrl ) {
1410                         $helpUrl = $to;
1411                 } else {
1412                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1413                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1414                 }
1415
1416                 $link = Html::rawElement(
1417                         'a',
1418                         [
1419                                 'href' => $helpUrl,
1420                                 'target' => '_blank',
1421                                 'class' => 'mw-helplink',
1422                         ],
1423                         $text
1424                 );
1425
1426                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1427         }
1428
1429         /**
1430          * Do not allow scripts which can be modified by wiki users to load on this page;
1431          * only allow scripts bundled with, or generated by, the software.
1432          * Site-wide styles are controlled by a config setting, since they can be
1433          * used to create a custom skin/theme, but not user-specific ones.
1434          *
1435          * @todo this should be given a more accurate name
1436          */
1437         public function disallowUserJs() {
1438                 $this->reduceAllowedModules(
1439                         ResourceLoaderModule::TYPE_SCRIPTS,
1440                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1441                 );
1442
1443                 // Site-wide styles are controlled by a config setting, see bug 71621
1444                 // for background on why. User styles are never allowed.
1445                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1446                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1447                 } else {
1448                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1449                 }
1450                 $this->reduceAllowedModules(
1451                         ResourceLoaderModule::TYPE_STYLES,
1452                         $styleOrigin
1453                 );
1454         }
1455
1456         /**
1457          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1458          * @see ResourceLoaderModule::$origin
1459          * @param string $type ResourceLoaderModule TYPE_ constant
1460          * @return int ResourceLoaderModule ORIGIN_ class constant
1461          */
1462         public function getAllowedModules( $type ) {
1463                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1464                         return min( array_values( $this->mAllowedModules ) );
1465                 } else {
1466                         return isset( $this->mAllowedModules[$type] )
1467                                 ? $this->mAllowedModules[$type]
1468                                 : ResourceLoaderModule::ORIGIN_ALL;
1469                 }
1470         }
1471
1472         /**
1473          * Limit the highest level of CSS/JS untrustworthiness allowed.
1474          *
1475          * If passed the same or a higher level than the current level of untrustworthiness set, the
1476          * level will remain unchanged.
1477          *
1478          * @param string $type
1479          * @param int $level ResourceLoaderModule class constant
1480          */
1481         public function reduceAllowedModules( $type, $level ) {
1482                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1483         }
1484
1485         /**
1486          * Prepend $text to the body HTML
1487          *
1488          * @param string $text HTML
1489          */
1490         public function prependHTML( $text ) {
1491                 $this->mBodytext = $text . $this->mBodytext;
1492         }
1493
1494         /**
1495          * Append $text to the body HTML
1496          *
1497          * @param string $text HTML
1498          */
1499         public function addHTML( $text ) {
1500                 $this->mBodytext .= $text;
1501         }
1502
1503         /**
1504          * Shortcut for adding an Html::element via addHTML.
1505          *
1506          * @since 1.19
1507          *
1508          * @param string $element
1509          * @param array $attribs
1510          * @param string $contents
1511          */
1512         public function addElement( $element, array $attribs = [], $contents = '' ) {
1513                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1514         }
1515
1516         /**
1517          * Clear the body HTML
1518          */
1519         public function clearHTML() {
1520                 $this->mBodytext = '';
1521         }
1522
1523         /**
1524          * Get the body HTML
1525          *
1526          * @return string HTML
1527          */
1528         public function getHTML() {
1529                 return $this->mBodytext;
1530         }
1531
1532         /**
1533          * Get/set the ParserOptions object to use for wikitext parsing
1534          *
1535          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1536          *   current ParserOption object
1537          * @return ParserOptions
1538          */
1539         public function parserOptions( $options = null ) {
1540                 if ( $options !== null && !empty( $options->isBogus ) ) {
1541                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1542                         // been changed somehow, and keep it if so.
1543                         $anonPO = ParserOptions::newFromAnon();
1544                         $anonPO->setEditSection( false );
1545                         if ( !$options->matches( $anonPO ) ) {
1546                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1547                                 $options->isBogus = false;
1548                         }
1549                 }
1550
1551                 if ( !$this->mParserOptions ) {
1552                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1553                                 // $wgUser isn't unstubbable yet, so don't try to get a
1554                                 // ParserOptions for it. And don't cache this ParserOptions
1555                                 // either.
1556                                 $po = ParserOptions::newFromAnon();
1557                                 $po->setEditSection( false );
1558                                 $po->isBogus = true;
1559                                 if ( $options !== null ) {
1560                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1561                                 }
1562                                 return $po;
1563                         }
1564
1565                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1566                         $this->mParserOptions->setEditSection( false );
1567                 }
1568
1569                 if ( $options !== null && !empty( $options->isBogus ) ) {
1570                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1571                         // thing.
1572                         return wfSetVar( $this->mParserOptions, null, true );
1573                 } else {
1574                         return wfSetVar( $this->mParserOptions, $options );
1575                 }
1576         }
1577
1578         /**
1579          * Set the revision ID which will be seen by the wiki text parser
1580          * for things such as embedded {{REVISIONID}} variable use.
1581          *
1582          * @param int|null $revid An positive integer, or null
1583          * @return mixed Previous value
1584          */
1585         public function setRevisionId( $revid ) {
1586                 $val = is_null( $revid ) ? null : intval( $revid );
1587                 return wfSetVar( $this->mRevisionId, $val );
1588         }
1589
1590         /**
1591          * Get the displayed revision ID
1592          *
1593          * @return int
1594          */
1595         public function getRevisionId() {
1596                 return $this->mRevisionId;
1597         }
1598
1599         /**
1600          * Set the timestamp of the revision which will be displayed. This is used
1601          * to avoid a extra DB call in Skin::lastModified().
1602          *
1603          * @param string|null $timestamp
1604          * @return mixed Previous value
1605          */
1606         public function setRevisionTimestamp( $timestamp ) {
1607                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1608         }
1609
1610         /**
1611          * Get the timestamp of displayed revision.
1612          * This will be null if not filled by setRevisionTimestamp().
1613          *
1614          * @return string|null
1615          */
1616         public function getRevisionTimestamp() {
1617                 return $this->mRevisionTimestamp;
1618         }
1619
1620         /**
1621          * Set the displayed file version
1622          *
1623          * @param File|bool $file
1624          * @return mixed Previous value
1625          */
1626         public function setFileVersion( $file ) {
1627                 $val = null;
1628                 if ( $file instanceof File && $file->exists() ) {
1629                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1630                 }
1631                 return wfSetVar( $this->mFileVersion, $val, true );
1632         }
1633
1634         /**
1635          * Get the displayed file version
1636          *
1637          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1638          */
1639         public function getFileVersion() {
1640                 return $this->mFileVersion;
1641         }
1642
1643         /**
1644          * Get the templates used on this page
1645          *
1646          * @return array (namespace => dbKey => revId)
1647          * @since 1.18
1648          */
1649         public function getTemplateIds() {
1650                 return $this->mTemplateIds;
1651         }
1652
1653         /**
1654          * Get the files used on this page
1655          *
1656          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1657          * @since 1.18
1658          */
1659         public function getFileSearchOptions() {
1660                 return $this->mImageTimeKeys;
1661         }
1662
1663         /**
1664          * Convert wikitext to HTML and add it to the buffer
1665          * Default assumes that the current page title will be used.
1666          *
1667          * @param string $text
1668          * @param bool $linestart Is this the start of a line?
1669          * @param bool $interface Is this text in the user interface language?
1670          * @throws MWException
1671          */
1672         public function addWikiText( $text, $linestart = true, $interface = true ) {
1673                 $title = $this->getTitle(); // Work around E_STRICT
1674                 if ( !$title ) {
1675                         throw new MWException( 'Title is null' );
1676                 }
1677                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1678         }
1679
1680         /**
1681          * Add wikitext with a custom Title object
1682          *
1683          * @param string $text Wikitext
1684          * @param Title $title
1685          * @param bool $linestart Is this the start of a line?
1686          */
1687         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1688                 $this->addWikiTextTitle( $text, $title, $linestart );
1689         }
1690
1691         /**
1692          * Add wikitext with a custom Title object and tidy enabled.
1693          *
1694          * @param string $text Wikitext
1695          * @param Title $title
1696          * @param bool $linestart Is this the start of a line?
1697          */
1698         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1699                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1700         }
1701
1702         /**
1703          * Add wikitext with tidy enabled
1704          *
1705          * @param string $text Wikitext
1706          * @param bool $linestart Is this the start of a line?
1707          */
1708         public function addWikiTextTidy( $text, $linestart = true ) {
1709                 $title = $this->getTitle();
1710                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1711         }
1712
1713         /**
1714          * Add wikitext with a custom Title object
1715          *
1716          * @param string $text Wikitext
1717          * @param Title $title
1718          * @param bool $linestart Is this the start of a line?
1719          * @param bool $tidy Whether to use tidy
1720          * @param bool $interface Whether it is an interface message
1721          *   (for example disables conversion)
1722          */
1723         public function addWikiTextTitle( $text, Title $title, $linestart,
1724                 $tidy = false, $interface = false
1725         ) {
1726                 global $wgParser;
1727
1728                 $popts = $this->parserOptions();
1729                 $oldTidy = $popts->setTidy( $tidy );
1730                 $popts->setInterfaceMessage( (bool)$interface );
1731
1732                 $parserOutput = $wgParser->getFreshParser()->parse(
1733                         $text, $title, $popts,
1734                         $linestart, true, $this->mRevisionId
1735                 );
1736
1737                 $popts->setTidy( $oldTidy );
1738
1739                 $this->addParserOutput( $parserOutput );
1740         }
1741
1742         /**
1743          * Add a ParserOutput object, but without Html.
1744          *
1745          * @deprecated since 1.24, use addParserOutputMetadata() instead.
1746          * @param ParserOutput $parserOutput
1747          */
1748         public function addParserOutputNoText( $parserOutput ) {
1749                 wfDeprecated( __METHOD__, '1.24' );
1750                 $this->addParserOutputMetadata( $parserOutput );
1751         }
1752
1753         /**
1754          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1755          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1756          * and so on.
1757          *
1758          * @since 1.24
1759          * @param ParserOutput $parserOutput
1760          */
1761         public function addParserOutputMetadata( $parserOutput ) {
1762                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1763                 $this->addCategoryLinks( $parserOutput->getCategories() );
1764                 $this->setIndicators( $parserOutput->getIndicators() );
1765                 $this->mNewSectionLink = $parserOutput->getNewSection();
1766                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1767
1768                 if ( !$parserOutput->isCacheable() ) {
1769                         $this->enableClientCache( false );
1770                 }
1771                 $this->mNoGallery = $parserOutput->getNoGallery();
1772                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1773                 $this->addModules( $parserOutput->getModules() );
1774                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1775                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1776                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1777                 $this->mPreventClickjacking = $this->mPreventClickjacking
1778                         || $parserOutput->preventClickjacking();
1779
1780                 // Template versioning...
1781                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1782                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1783                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1784                         } else {
1785                                 $this->mTemplateIds[$ns] = $dbks;
1786                         }
1787                 }
1788                 // File versioning...
1789                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1790                         $this->mImageTimeKeys[$dbk] = $data;
1791                 }
1792
1793                 // Hooks registered in the object
1794                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1795                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1796                         list( $hookName, $data ) = $hookInfo;
1797                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1798                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1799                         }
1800                 }
1801
1802                 // enable OOUI if requested via ParserOutput
1803                 if ( $parserOutput->getEnableOOUI() ) {
1804                         $this->enableOOUI();
1805                 }
1806
1807                 // Link flags are ignored for now, but may in the future be
1808                 // used to mark individual language links.
1809                 $linkFlags = [];
1810                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1811                 Hooks::run( 'OutputPageParserOutput', [ &$this, $parserOutput ] );
1812         }
1813
1814         /**
1815          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1816          * ParserOutput object, without any other metadata.
1817          *
1818          * @since 1.24
1819          * @param ParserOutput $parserOutput
1820          */
1821         public function addParserOutputContent( $parserOutput ) {
1822                 $this->addParserOutputText( $parserOutput );
1823
1824                 $this->addModules( $parserOutput->getModules() );
1825                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1826                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1827
1828                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1829         }
1830
1831         /**
1832          * Add the HTML associated with a ParserOutput object, without any metadata.
1833          *
1834          * @since 1.24
1835          * @param ParserOutput $parserOutput
1836          */
1837         public function addParserOutputText( $parserOutput ) {
1838                 $text = $parserOutput->getText();
1839                 Hooks::run( 'OutputPageBeforeHTML', [ &$this, &$text ] );
1840                 $this->addHTML( $text );
1841         }
1842
1843         /**
1844          * Add everything from a ParserOutput object.
1845          *
1846          * @param ParserOutput $parserOutput
1847          */
1848         function addParserOutput( $parserOutput ) {
1849                 $this->addParserOutputMetadata( $parserOutput );
1850                 $parserOutput->setTOCEnabled( $this->mEnableTOC );
1851
1852                 // Touch section edit links only if not previously disabled
1853                 if ( $parserOutput->getEditSectionTokens() ) {
1854                         $parserOutput->setEditSectionTokens( $this->mEnableSectionEditLinks );
1855                 }
1856
1857                 $this->addParserOutputText( $parserOutput );
1858         }
1859
1860         /**
1861          * Add the output of a QuickTemplate to the output buffer
1862          *
1863          * @param QuickTemplate $template
1864          */
1865         public function addTemplate( &$template ) {
1866                 $this->addHTML( $template->getHTML() );
1867         }
1868
1869         /**
1870          * Parse wikitext and return the HTML.
1871          *
1872          * @param string $text
1873          * @param bool $linestart Is this the start of a line?
1874          * @param bool $interface Use interface language ($wgLang instead of
1875          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1876          *   This also disables LanguageConverter.
1877          * @param Language $language Target language object, will override $interface
1878          * @throws MWException
1879          * @return string HTML
1880          */
1881         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1882                 global $wgParser;
1883
1884                 if ( is_null( $this->getTitle() ) ) {
1885                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1886                 }
1887
1888                 $popts = $this->parserOptions();
1889                 if ( $interface ) {
1890                         $popts->setInterfaceMessage( true );
1891                 }
1892                 if ( $language !== null ) {
1893                         $oldLang = $popts->setTargetLanguage( $language );
1894                 }
1895
1896                 $parserOutput = $wgParser->getFreshParser()->parse(
1897                         $text, $this->getTitle(), $popts,
1898                         $linestart, true, $this->mRevisionId
1899                 );
1900
1901                 if ( $interface ) {
1902                         $popts->setInterfaceMessage( false );
1903                 }
1904                 if ( $language !== null ) {
1905                         $popts->setTargetLanguage( $oldLang );
1906                 }
1907
1908                 return $parserOutput->getText();
1909         }
1910
1911         /**
1912          * Parse wikitext, strip paragraphs, and return the HTML.
1913          *
1914          * @param string $text
1915          * @param bool $linestart Is this the start of a line?
1916          * @param bool $interface Use interface language ($wgLang instead of
1917          *   $wgContLang) while parsing language sensitive magic
1918          *   words like GRAMMAR and PLURAL
1919          * @return string HTML
1920          */
1921         public function parseInline( $text, $linestart = true, $interface = false ) {
1922                 $parsed = $this->parse( $text, $linestart, $interface );
1923                 return Parser::stripOuterParagraph( $parsed );
1924         }
1925
1926         /**
1927          * @param $maxage
1928          * @deprecated since 1.27 Use setCdnMaxage() instead
1929          */
1930         public function setSquidMaxage( $maxage ) {
1931                 $this->setCdnMaxage( $maxage );
1932         }
1933
1934         /**
1935          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1936          *
1937          * @param int $maxage Maximum cache time on the CDN, in seconds.
1938          */
1939         public function setCdnMaxage( $maxage ) {
1940                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1941         }
1942
1943         /**
1944          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1945          *
1946          * @param int $maxage Maximum cache time on the CDN, in seconds
1947          * @since 1.27
1948          */
1949         public function lowerCdnMaxage( $maxage ) {
1950                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
1951                 $this->setCdnMaxage( $this->mCdnMaxage );
1952         }
1953
1954         /**
1955          * Get TTL in [$minTTL,$maxTTL] in pass it to lowerCdnMaxage()
1956          *
1957          * This sets and returns $minTTL if $mtime is false or null. Otherwise,
1958          * the TTL is higher the older the $mtime timestamp is. Essentially, the
1959          * TTL is 90% of the age of the object, subject to the min and max.
1960          *
1961          * @param string|integer|float|bool|null $mtime Last-Modified timestamp
1962          * @param integer $minTTL Mimimum TTL in seconds [default: 1 minute]
1963          * @param integer $maxTTL Maximum TTL in seconds [default: $wgSquidMaxage]
1964          * @return integer TTL in seconds
1965          * @since 1.28
1966          */
1967         public function adaptCdnTTL( $mtime, $minTTL = 0, $maxTTL = 0 ) {
1968                 $minTTL = $minTTL ?: IExpiringStore::TTL_MINUTE;
1969                 $maxTTL = $maxTTL ?: $this->getConfig()->get( 'SquidMaxage' );
1970
1971                 if ( $mtime === null || $mtime === false ) {
1972                         return $minTTL; // entity does not exist
1973                 }
1974
1975                 $age = time() - wfTimestamp( TS_UNIX, $mtime );
1976                 $adaptiveTTL = max( .9 * $age, $minTTL );
1977                 $adaptiveTTL = min( $adaptiveTTL, $maxTTL );
1978
1979                 $this->lowerCdnMaxage( (int)$adaptiveTTL );
1980
1981                 return $adaptiveTTL;
1982         }
1983
1984         /**
1985          * Use enableClientCache(false) to force it to send nocache headers
1986          *
1987          * @param bool $state
1988          *
1989          * @return bool
1990          */
1991         public function enableClientCache( $state ) {
1992                 return wfSetVar( $this->mEnableClientCache, $state );
1993         }
1994
1995         /**
1996          * Get the list of cookies that will influence on the cache
1997          *
1998          * @return array
1999          */
2000         function getCacheVaryCookies() {
2001                 static $cookies;
2002                 if ( $cookies === null ) {
2003                         $config = $this->getConfig();
2004                         $cookies = array_merge(
2005                                 SessionManager::singleton()->getVaryCookies(),
2006                                 [
2007                                         'forceHTTPS',
2008                                 ],
2009                                 $config->get( 'CacheVaryCookies' )
2010                         );
2011                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
2012                 }
2013                 return $cookies;
2014         }
2015
2016         /**
2017          * Check if the request has a cache-varying cookie header
2018          * If it does, it's very important that we don't allow public caching
2019          *
2020          * @return bool
2021          */
2022         function haveCacheVaryCookies() {
2023                 $request = $this->getRequest();
2024                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
2025                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
2026                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
2027                                 return true;
2028                         }
2029                 }
2030                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
2031                 return false;
2032         }
2033
2034         /**
2035          * Add an HTTP header that will influence on the cache
2036          *
2037          * @param string $header Header name
2038          * @param string[]|null $option Options for the Key header. See
2039          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
2040          * for the list of valid options.
2041          */
2042         public function addVaryHeader( $header, array $option = null ) {
2043                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
2044                         $this->mVaryHeader[$header] = [];
2045                 }
2046                 if ( !is_array( $option ) ) {
2047                         $option = [];
2048                 }
2049                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2050         }
2051
2052         /**
2053          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2054          * such as Accept-Encoding or Cookie
2055          *
2056          * @return string
2057          */
2058         public function getVaryHeader() {
2059                 // If we vary on cookies, let's make sure it's always included here too.
2060                 if ( $this->getCacheVaryCookies() ) {
2061                         $this->addVaryHeader( 'Cookie' );
2062                 }
2063
2064                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2065                         $this->addVaryHeader( $header, $options );
2066                 }
2067                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2068         }
2069
2070         /**
2071          * Get a complete Key header
2072          *
2073          * @return string
2074          */
2075         public function getKeyHeader() {
2076                 $cvCookies = $this->getCacheVaryCookies();
2077
2078                 $cookiesOption = [];
2079                 foreach ( $cvCookies as $cookieName ) {
2080                         $cookiesOption[] = 'param=' . $cookieName;
2081                 }
2082                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2083
2084                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2085                         $this->addVaryHeader( $header, $options );
2086                 }
2087
2088                 $headers = [];
2089                 foreach ( $this->mVaryHeader as $header => $option ) {
2090                         $newheader = $header;
2091                         if ( is_array( $option ) && count( $option ) > 0 ) {
2092                                 $newheader .= ';' . implode( ';', $option );
2093                         }
2094                         $headers[] = $newheader;
2095                 }
2096                 $key = 'Key: ' . implode( ',', $headers );
2097
2098                 return $key;
2099         }
2100
2101         /**
2102          * T23672: Add Accept-Language to Vary and Key headers
2103          * if there's no 'variant' parameter existed in GET.
2104          *
2105          * For example:
2106          *   /w/index.php?title=Main_page should always be served; but
2107          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2108          */
2109         function addAcceptLanguage() {
2110                 $title = $this->getTitle();
2111                 if ( !$title instanceof Title ) {
2112                         return;
2113                 }
2114
2115                 $lang = $title->getPageLanguage();
2116                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2117                         $variants = $lang->getVariants();
2118                         $aloption = [];
2119                         foreach ( $variants as $variant ) {
2120                                 if ( $variant === $lang->getCode() ) {
2121                                         continue;
2122                                 } else {
2123                                         $aloption[] = 'substr=' . $variant;
2124
2125                                         // IE and some other browsers use BCP 47 standards in
2126                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2127                                         // We should handle these too.
2128                                         $variantBCP47 = wfBCP47( $variant );
2129                                         if ( $variantBCP47 !== $variant ) {
2130                                                 $aloption[] = 'substr=' . $variantBCP47;
2131                                         }
2132                                 }
2133                         }
2134                         $this->addVaryHeader( 'Accept-Language', $aloption );
2135                 }
2136         }
2137
2138         /**
2139          * Set a flag which will cause an X-Frame-Options header appropriate for
2140          * edit pages to be sent. The header value is controlled by
2141          * $wgEditPageFrameOptions.
2142          *
2143          * This is the default for special pages. If you display a CSRF-protected
2144          * form on an ordinary view page, then you need to call this function.
2145          *
2146          * @param bool $enable
2147          */
2148         public function preventClickjacking( $enable = true ) {
2149                 $this->mPreventClickjacking = $enable;
2150         }
2151
2152         /**
2153          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2154          * This can be called from pages which do not contain any CSRF-protected
2155          * HTML form.
2156          */
2157         public function allowClickjacking() {
2158                 $this->mPreventClickjacking = false;
2159         }
2160
2161         /**
2162          * Get the prevent-clickjacking flag
2163          *
2164          * @since 1.24
2165          * @return bool
2166          */
2167         public function getPreventClickjacking() {
2168                 return $this->mPreventClickjacking;
2169         }
2170
2171         /**
2172          * Get the X-Frame-Options header value (without the name part), or false
2173          * if there isn't one. This is used by Skin to determine whether to enable
2174          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2175          *
2176          * @return string
2177          */
2178         public function getFrameOptions() {
2179                 $config = $this->getConfig();
2180                 if ( $config->get( 'BreakFrames' ) ) {
2181                         return 'DENY';
2182                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2183                         return $config->get( 'EditPageFrameOptions' );
2184                 }
2185                 return false;
2186         }
2187
2188         /**
2189          * Send cache control HTTP headers
2190          */
2191         public function sendCacheControl() {
2192                 $response = $this->getRequest()->response();
2193                 $config = $this->getConfig();
2194
2195                 $this->addVaryHeader( 'Cookie' );
2196                 $this->addAcceptLanguage();
2197
2198                 # don't serve compressed data to clients who can't handle it
2199                 # maintain different caches for logged-in users and non-logged in ones
2200                 $response->header( $this->getVaryHeader() );
2201
2202                 if ( $config->get( 'UseKeyHeader' ) ) {
2203                         $response->header( $this->getKeyHeader() );
2204                 }
2205
2206                 if ( $this->mEnableClientCache ) {
2207                         if (
2208                                 $config->get( 'UseSquid' ) &&
2209                                 !$response->hasCookies() &&
2210                                 !SessionManager::getGlobalSession()->isPersistent() &&
2211                                 !$this->isPrintable() &&
2212                                 $this->mCdnMaxage != 0 &&
2213                                 !$this->haveCacheVaryCookies()
2214                         ) {
2215                                 if ( $config->get( 'UseESI' ) ) {
2216                                         # We'll purge the proxy cache explicitly, but require end user agents
2217                                         # to revalidate against the proxy on each visit.
2218                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2219                                         wfDebug( __METHOD__ .
2220                                                 ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2221                                         # start with a shorter timeout for initial testing
2222                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2223                                         $response->header(
2224                                                 "Surrogate-Control: max-age={$config->get( 'SquidMaxage' )}" .
2225                                                 "+{$this->mCdnMaxage}, content=\"ESI/1.0\""
2226                                         );
2227                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2228                                 } else {
2229                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2230                                         # to revalidate against the proxy on each visit.
2231                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2232                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2233                                         wfDebug( __METHOD__ .
2234                                                 ": local proxy caching; {$this->mLastModified} **", 'private' );
2235                                         # start with a shorter timeout for initial testing
2236                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2237                                         $response->header( "Cache-Control: " .
2238                                                 "s-maxage={$this->mCdnMaxage}, must-revalidate, max-age=0" );
2239                                 }
2240                         } else {
2241                                 # We do want clients to cache if they can, but they *must* check for updates
2242                                 # on revisiting the page.
2243                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2244                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2245                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2246                         }
2247                         if ( $this->mLastModified ) {
2248                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2249                         }
2250                 } else {
2251                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2252
2253                         # In general, the absence of a last modified header should be enough to prevent
2254                         # the client from using its cache. We send a few other things just to make sure.
2255                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2256                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2257                         $response->header( 'Pragma: no-cache' );
2258                 }
2259         }
2260
2261         /**
2262          * Finally, all the text has been munged and accumulated into
2263          * the object, let's actually output it:
2264          *
2265          * @param bool $return Set to true to get the result as a string rather than sending it
2266          * @return string|null
2267          * @throws Exception
2268          * @throws FatalError
2269          * @throws MWException
2270          */
2271         public function output( $return = false ) {
2272                 global $wgContLang;
2273
2274                 if ( $this->mDoNothing ) {
2275                         return $return ? '' : null;
2276                 }
2277
2278                 $response = $this->getRequest()->response();
2279                 $config = $this->getConfig();
2280
2281                 if ( $this->mRedirect != '' ) {
2282                         # Standards require redirect URLs to be absolute
2283                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2284
2285                         $redirect = $this->mRedirect;
2286                         $code = $this->mRedirectCode;
2287
2288                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2289                                 if ( $code == '301' || $code == '303' ) {
2290                                         if ( !$config->get( 'DebugRedirects' ) ) {
2291                                                 $response->statusHeader( $code );
2292                                         }
2293                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2294                                 }
2295                                 if ( $config->get( 'VaryOnXFP' ) ) {
2296                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2297                                 }
2298                                 $this->sendCacheControl();
2299
2300                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2301                                 if ( $config->get( 'DebugRedirects' ) ) {
2302                                         $url = htmlspecialchars( $redirect );
2303                                         print "<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2304                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2305                                         print "</body>\n</html>\n";
2306                                 } else {
2307                                         $response->header( 'Location: ' . $redirect );
2308                                 }
2309                         }
2310
2311                         return $return ? '' : null;
2312                 } elseif ( $this->mStatusCode ) {
2313                         $response->statusHeader( $this->mStatusCode );
2314                 }
2315
2316                 # Buffer output; final headers may depend on later processing
2317                 ob_start();
2318
2319                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2320                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2321
2322                 // Avoid Internet Explorer "compatibility view" in IE 8-10, so that
2323                 // jQuery etc. can work correctly.
2324                 $response->header( 'X-UA-Compatible: IE=Edge' );
2325
2326                 // Prevent framing, if requested
2327                 $frameOptions = $this->getFrameOptions();
2328                 if ( $frameOptions ) {
2329                         $response->header( "X-Frame-Options: $frameOptions" );
2330                 }
2331
2332                 if ( $this->mArticleBodyOnly ) {
2333                         echo $this->mBodytext;
2334                 } else {
2335                         $sk = $this->getSkin();
2336                         // add skin specific modules
2337                         $modules = $sk->getDefaultModules();
2338
2339                         // Enforce various default modules for all pages and all skins
2340                         $coreModules = [
2341                                 // Keep this list as small as possible
2342                                 'site',
2343                                 'mediawiki.page.startup',
2344                                 'mediawiki.user',
2345                         ];
2346
2347                         // Support for high-density display images if enabled
2348                         if ( $config->get( 'ResponsiveImages' ) ) {
2349                                 $coreModules[] = 'mediawiki.hidpi';
2350                         }
2351
2352                         $this->addModules( $coreModules );
2353                         foreach ( $modules as $group ) {
2354                                 $this->addModules( $group );
2355                         }
2356                         MWDebug::addModules( $this );
2357
2358                         // Hook that allows last minute changes to the output page, e.g.
2359                         // adding of CSS or Javascript by extensions.
2360                         Hooks::run( 'BeforePageDisplay', [ &$this, &$sk ] );
2361
2362                         try {
2363                                 $sk->outputPage();
2364                         } catch ( Exception $e ) {
2365                                 ob_end_clean(); // bug T129657
2366                                 throw $e;
2367                         }
2368                 }
2369
2370                 try {
2371                         // This hook allows last minute changes to final overall output by modifying output buffer
2372                         Hooks::run( 'AfterFinalPageOutput', [ $this ] );
2373                 } catch ( Exception $e ) {
2374                         ob_end_clean(); // bug T129657
2375                         throw $e;
2376                 }
2377
2378                 $this->sendCacheControl();
2379
2380                 if ( $return ) {
2381                         return ob_get_clean();
2382                 } else {
2383                         ob_end_flush();
2384                         return null;
2385                 }
2386         }
2387
2388         /**
2389          * Prepare this object to display an error page; disable caching and
2390          * indexing, clear the current text and redirect, set the page's title
2391          * and optionally an custom HTML title (content of the "<title>" tag).
2392          *
2393          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2394          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2395          *                   optional, if not passed the "<title>" attribute will be
2396          *                   based on $pageTitle
2397          */
2398         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2399                 $this->setPageTitle( $pageTitle );
2400                 if ( $htmlTitle !== false ) {
2401                         $this->setHTMLTitle( $htmlTitle );
2402                 }
2403                 $this->setRobotPolicy( 'noindex,nofollow' );
2404                 $this->setArticleRelated( false );
2405                 $this->enableClientCache( false );
2406                 $this->mRedirect = '';
2407                 $this->clearSubtitle();
2408                 $this->clearHTML();
2409         }
2410
2411         /**
2412          * Output a standard error page
2413          *
2414          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2415          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2416          * showErrorPage( 'titlemsg', $messageObject );
2417          * showErrorPage( $titleMessageObject, $messageObject );
2418          *
2419          * @param string|Message $title Message key (string) for page title, or a Message object
2420          * @param string|Message $msg Message key (string) for page text, or a Message object
2421          * @param array $params Message parameters; ignored if $msg is a Message object
2422          */
2423         public function showErrorPage( $title, $msg, $params = [] ) {
2424                 if ( !$title instanceof Message ) {
2425                         $title = $this->msg( $title );
2426                 }
2427
2428                 $this->prepareErrorPage( $title );
2429
2430                 if ( $msg instanceof Message ) {
2431                         if ( $params !== [] ) {
2432                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2433                                         . 'is discarded when the $msg argument is a Message object instead of '
2434                                         . 'a string.', E_USER_NOTICE );
2435                         }
2436                         $this->addHTML( $msg->parseAsBlock() );
2437                 } else {
2438                         $this->addWikiMsgArray( $msg, $params );
2439                 }
2440
2441                 $this->returnToMain();
2442         }
2443
2444         /**
2445          * Output a standard permission error page
2446          *
2447          * @param array $errors Error message keys or [key, param...] arrays
2448          * @param string $action Action that was denied or null if unknown
2449          */
2450         public function showPermissionsErrorPage( array $errors, $action = null ) {
2451                 foreach ( $errors as $key => $error ) {
2452                         $errors[$key] = (array)$error;
2453                 }
2454
2455                 // For some action (read, edit, create and upload), display a "login to do this action"
2456                 // error if all of the following conditions are met:
2457                 // 1. the user is not logged in
2458                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2459                 // 3. the error can be avoided simply by logging in
2460                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2461                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2462                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2463                         && ( User::groupHasPermission( 'user', $action )
2464                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2465                 ) {
2466                         $displayReturnto = null;
2467
2468                         # Due to bug 32276, if a user does not have read permissions,
2469                         # $this->getTitle() will just give Special:Badtitle, which is
2470                         # not especially useful as a returnto parameter. Use the title
2471                         # from the request instead, if there was one.
2472                         $request = $this->getRequest();
2473                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2474                         if ( $action == 'edit' ) {
2475                                 $msg = 'whitelistedittext';
2476                                 $displayReturnto = $returnto;
2477                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2478                                 $msg = 'nocreatetext';
2479                         } elseif ( $action == 'upload' ) {
2480                                 $msg = 'uploadnologintext';
2481                         } else { # Read
2482                                 $msg = 'loginreqpagetext';
2483                                 $displayReturnto = Title::newMainPage();
2484                         }
2485
2486                         $query = [];
2487
2488                         if ( $returnto ) {
2489                                 $query['returnto'] = $returnto->getPrefixedText();
2490
2491                                 if ( !$request->wasPosted() ) {
2492                                         $returntoquery = $request->getValues();
2493                                         unset( $returntoquery['title'] );
2494                                         unset( $returntoquery['returnto'] );
2495                                         unset( $returntoquery['returntoquery'] );
2496                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2497                                 }
2498                         }
2499                         $loginLink = Linker::linkKnown(
2500                                 SpecialPage::getTitleFor( 'Userlogin' ),
2501                                 $this->msg( 'loginreqlink' )->escaped(),
2502                                 [],
2503                                 $query
2504                         );
2505
2506                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2507                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2508
2509                         # Don't return to a page the user can't read otherwise
2510                         # we'll end up in a pointless loop
2511                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2512                                 $this->returnToMain( null, $displayReturnto );
2513                         }
2514                 } else {
2515                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2516                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2517                 }
2518         }
2519
2520         /**
2521          * Display an error page indicating that a given version of MediaWiki is
2522          * required to use it
2523          *
2524          * @param mixed $version The version of MediaWiki needed to use the page
2525          */
2526         public function versionRequired( $version ) {
2527                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2528
2529                 $this->addWikiMsg( 'versionrequiredtext', $version );
2530                 $this->returnToMain();
2531         }
2532
2533         /**
2534          * Format a list of error messages
2535          *
2536          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2537          * @param string $action Action that was denied or null if unknown
2538          * @return string The wikitext error-messages, formatted into a list.
2539          */
2540         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2541                 if ( $action == null ) {
2542                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2543                 } else {
2544                         $action_desc = $this->msg( "action-$action" )->plain();
2545                         $text = $this->msg(
2546                                 'permissionserrorstext-withaction',
2547                                 count( $errors ),
2548                                 $action_desc
2549                         )->plain() . "\n\n";
2550                 }
2551
2552                 if ( count( $errors ) > 1 ) {
2553                         $text .= '<ul class="permissions-errors">' . "\n";
2554
2555                         foreach ( $errors as $error ) {
2556                                 $text .= '<li>';
2557                                 $text .= call_user_func_array( [ $this, 'msg' ], $error )->plain();
2558                                 $text .= "</li>\n";
2559                         }
2560                         $text .= '</ul>';
2561                 } else {
2562                         $text .= "<div class=\"permissions-errors\">\n" .
2563                                         call_user_func_array( [ $this, 'msg' ], reset( $errors ) )->plain() .
2564                                         "\n</div>";
2565                 }
2566
2567                 return $text;
2568         }
2569
2570         /**
2571          * Display a page stating that the Wiki is in read-only mode.
2572          * Should only be called after wfReadOnly() has returned true.
2573          *
2574          * Historically, this function was used to show the source of the page that the user
2575          * was trying to edit and _also_ permissions error messages. The relevant code was
2576          * moved into EditPage in 1.19 (r102024 / d83c2a431c2a) and removed here in 1.25.
2577          *
2578          * @deprecated since 1.25; throw the exception directly
2579          * @throws ReadOnlyError
2580          */
2581         public function readOnlyPage() {
2582                 if ( func_num_args() > 0 ) {
2583                         throw new MWException( __METHOD__ . ' no longer accepts arguments since 1.25.' );
2584                 }
2585
2586                 throw new ReadOnlyError;
2587         }
2588
2589         /**
2590          * Turn off regular page output and return an error response
2591          * for when rate limiting has triggered.
2592          *
2593          * @deprecated since 1.25; throw the exception directly
2594          */
2595         public function rateLimited() {
2596                 wfDeprecated( __METHOD__, '1.25' );
2597                 throw new ThrottledError;
2598         }
2599
2600         /**
2601          * Show a warning about replica DB lag
2602          *
2603          * If the lag is higher than $wgSlaveLagCritical seconds,
2604          * then the warning is a bit more obvious. If the lag is
2605          * lower than $wgSlaveLagWarning, then no warning is shown.
2606          *
2607          * @param int $lag Slave lag
2608          */
2609         public function showLagWarning( $lag ) {
2610                 $config = $this->getConfig();
2611                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2612                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2613                         $message = $lag < $config->get( 'SlaveLagCritical' )
2614                                 ? 'lag-warn-normal'
2615                                 : 'lag-warn-high';
2616                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2617                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2618                 }
2619         }
2620
2621         public function showFatalError( $message ) {
2622                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2623
2624                 $this->addHTML( $message );
2625         }
2626
2627         public function showUnexpectedValueError( $name, $val ) {
2628                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
2629         }
2630
2631         public function showFileCopyError( $old, $new ) {
2632                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
2633         }
2634
2635         public function showFileRenameError( $old, $new ) {
2636                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
2637         }
2638
2639         public function showFileDeleteError( $name ) {
2640                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
2641         }
2642
2643         public function showFileNotFoundError( $name ) {
2644                 $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
2645         }
2646
2647         /**
2648          * Add a "return to" link pointing to a specified title
2649          *
2650          * @param Title $title Title to link
2651          * @param array $query Query string parameters
2652          * @param string $text Text of the link (input is not escaped)
2653          * @param array $options Options array to pass to Linker
2654          */
2655         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2656                 $link = $this->msg( 'returnto' )->rawParams(
2657                         Linker::link( $title, $text, [], $query, $options ) )->escaped();
2658                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2659         }
2660
2661         /**
2662          * Add a "return to" link pointing to a specified title,
2663          * or the title indicated in the request, or else the main page
2664          *
2665          * @param mixed $unused
2666          * @param Title|string $returnto Title or String to return to
2667          * @param string $returntoquery Query string for the return to link
2668          */
2669         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2670                 if ( $returnto == null ) {
2671                         $returnto = $this->getRequest()->getText( 'returnto' );
2672                 }
2673
2674                 if ( $returntoquery == null ) {
2675                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2676                 }
2677
2678                 if ( $returnto === '' ) {
2679                         $returnto = Title::newMainPage();
2680                 }
2681
2682                 if ( is_object( $returnto ) ) {
2683                         $titleObj = $returnto;
2684                 } else {
2685                         $titleObj = Title::newFromText( $returnto );
2686                 }
2687                 if ( !is_object( $titleObj ) ) {
2688                         $titleObj = Title::newMainPage();
2689                 }
2690
2691                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2692         }
2693
2694         private function getRlClientContext() {
2695                 if ( !$this->rlClientContext ) {
2696                         $query = ResourceLoader::makeLoaderQuery(
2697                                 [], // modules; not relevant
2698                                 $this->getLanguage()->getCode(),
2699                                 $this->getSkin()->getSkinName(),
2700                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2701                                 null, // version; not relevant
2702                                 ResourceLoader::inDebugMode(),
2703                                 null, // only; not relevant
2704                                 $this->isPrintable(),
2705                                 $this->getRequest()->getBool( 'handheld' )
2706                         );
2707                         $this->rlClientContext = new ResourceLoaderContext(
2708                                 $this->getResourceLoader(),
2709                                 new FauxRequest( $query )
2710                         );
2711                 }
2712                 return $this->rlClientContext;
2713         }
2714
2715         /**
2716          * Call this to freeze the module queue and JS config and create a formatter.
2717          *
2718          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2719          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2720          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2721          * the module filters retroactively. Skins and extension hooks may also add modules until very
2722          * late in the request lifecycle.
2723          *
2724          * @return ResourceLoaderClientHtml
2725          */
2726         public function getRlClient() {
2727                 if ( !$this->rlClient ) {
2728                         $context = $this->getRlClientContext();
2729                         $rl = $this->getResourceLoader();
2730                         $this->addModules( [
2731                                 'user.options',
2732                                 'user.tokens',
2733                         ] );
2734                         $this->addModuleStyles( [
2735                                 'site.styles',
2736                                 'noscript',
2737                                 'user.styles',
2738                                 'user.cssprefs',
2739                         ] );
2740                         $this->getSkin()->setupSkinUserCss( $this );
2741
2742                         // Prepare exempt modules for buildExemptModules()
2743                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2744                         $exemptStates = [];
2745                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2746
2747                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2748                         // Separate user-specific batch for improved cache-hit ratio.
2749                         $userBatch = [ 'user.styles', 'user' ];
2750                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2751                         $dbr = wfGetDB( DB_REPLICA );
2752                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2753                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2754
2755                         // Filter out modules handled by buildExemptModules()
2756                         $moduleStyles = array_filter( $moduleStyles,
2757                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2758                                         $module = $rl->getModule( $name );
2759                                         if ( $module ) {
2760                                                 if ( $name === 'user.styles' && $this->isUserCssPreview() ) {
2761                                                         $exemptStates[$name] = 'ready';
2762                                                         // Special case in buildExemptModules()
2763                                                         return false;
2764                                                 }
2765                                                 $group = $module->getGroup();
2766                                                 if ( isset( $exemptGroups[$group] ) ) {
2767                                                         $exemptStates[$name] = 'ready';
2768                                                         if ( !$module->isKnownEmpty( $context ) ) {
2769                                                                 // E.g. Don't output empty <styles>
2770                                                                 $exemptGroups[$group][] = $name;
2771                                                         }
2772                                                         return false;
2773                                                 }
2774                                         }
2775                                         return true;
2776                                 }
2777                         );
2778                         $this->rlExemptStyleModules = $exemptGroups;
2779
2780                         $isUserModuleFiltered = !$this->filterModules( [ 'user' ] );
2781                         // If this page filters out 'user', makeResourceLoaderLink will drop it.
2782                         // Avoid indefinite "loading" state or untrue "ready" state (T145368).
2783                         if ( !$isUserModuleFiltered ) {
2784                                 // Manually handled by getBottomScripts()
2785                                 $userModule = $rl->getModule( 'user' );
2786                                 $userState = $userModule->isKnownEmpty( $context ) && !$this->isUserJsPreview()
2787                                         ? 'ready'
2788                                         : 'loading';
2789                                 $this->rlUserModuleState = $exemptStates['user'] = $userState;
2790                         }
2791
2792                         $rlClient = new ResourceLoaderClientHtml( $context, $this->getTarget() );
2793                         $rlClient->setConfig( $this->getJSVars() );
2794                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2795                         $rlClient->setModuleStyles( $moduleStyles );
2796                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2797                         $rlClient->setExemptStates( $exemptStates );
2798                         $this->rlClient = $rlClient;
2799                 }
2800                 return $this->rlClient;
2801         }
2802
2803         /**
2804          * @param Skin $sk The given Skin
2805          * @param bool $includeStyle Unused
2806          * @return string The doctype, opening "<html>", and head element.
2807          */
2808         public function headElement( Skin $sk, $includeStyle = true ) {
2809                 global $wgContLang;
2810
2811                 $userdir = $this->getLanguage()->getDir();
2812                 $sitedir = $wgContLang->getDir();
2813
2814                 $pieces = [];
2815                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2816                         $this->getRlClient()->getDocumentAttributes(),
2817                         $sk->getHtmlElementAttributes()
2818                 ) );
2819                 $pieces[] = Html::openElement( 'head' );
2820
2821                 if ( $this->getHTMLTitle() == '' ) {
2822                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2823                 }
2824
2825                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2826                         // Add <meta charset="UTF-8">
2827                         // This should be before <title> since it defines the charset used by
2828                         // text including the text inside <title>.
2829                         // The spec recommends defining XHTML5's charset using the XML declaration
2830                         // instead of meta.
2831                         // Our XML declaration is output by Html::htmlHeader.
2832                         // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type
2833                         // https://html.spec.whatwg.org/multipage/semantics.html#charset
2834                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2835                 }
2836
2837                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2838                 $pieces[] = $this->getRlClient()->getHeadHtml();
2839                 $pieces[] = $this->buildExemptModules();
2840                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2841                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2842                 $pieces[] = Html::closeElement( 'head' );
2843
2844                 $bodyClasses = [];
2845                 $bodyClasses[] = 'mediawiki';
2846
2847                 # Classes for LTR/RTL directionality support
2848                 $bodyClasses[] = $userdir;
2849                 $bodyClasses[] = "sitedir-$sitedir";
2850
2851                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2852                         # A <body> class is probably not the best way to do this . . .
2853                         $bodyClasses[] = 'capitalize-all-nouns';
2854                 }
2855
2856                 // Parser feature migration class
2857                 // The idea is that this will eventually be removed, after the wikitext
2858                 // which requires it is cleaned up.
2859                 $bodyClasses[] = 'mw-hide-empty-elt';
2860
2861                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2862                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2863                 $bodyClasses[] =
2864                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2865
2866                 $bodyAttrs = [];
2867                 // While the implode() is not strictly needed, it's used for backwards compatibility
2868                 // (this used to be built as a string and hooks likely still expect that).
2869                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2870
2871                 // Allow skins and extensions to add body attributes they need
2872                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2873                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2874
2875                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2876
2877                 return self::combineWrappedStrings( $pieces );
2878         }
2879
2880         /**
2881          * Get a ResourceLoader object associated with this OutputPage
2882          *
2883          * @return ResourceLoader
2884          */
2885         public function getResourceLoader() {
2886                 if ( is_null( $this->mResourceLoader ) ) {
2887                         $this->mResourceLoader = new ResourceLoader(
2888                                 $this->getConfig(),
2889                                 LoggerFactory::getInstance( 'resourceloader' )
2890                         );
2891                 }
2892                 return $this->mResourceLoader;
2893         }
2894
2895         /**
2896          * Explicily load or embed modules on a page.
2897          *
2898          * @param array|string $modules One or more module names
2899          * @param string $only ResourceLoaderModule TYPE_ class constant
2900          * @param array $extraQuery [optional] Array with extra query parameters for the request
2901          * @return string|WrappedStringList HTML
2902          */
2903         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
2904                 // Apply 'target' and 'origin' filters
2905                 $modules = $this->filterModules( (array)$modules, null, $only );
2906
2907                 return ResourceLoaderClientHtml::makeLoad(
2908                         $this->getRlClientContext(),
2909                         $modules,
2910                         $only,
2911                         $extraQuery
2912                 );
2913         }
2914
2915         /**
2916          * Combine WrappedString chunks and filter out empty ones
2917          *
2918          * @param array $chunks
2919          * @return string|WrappedStringList HTML
2920          */
2921         protected static function combineWrappedStrings( array $chunks ) {
2922                 // Filter out empty values
2923                 $chunks = array_filter( $chunks, 'strlen' );
2924                 return WrappedString::join( "\n", $chunks );
2925         }
2926
2927         private function isUserJsPreview() {
2928                 return $this->getConfig()->get( 'AllowUserJs' )
2929                         && $this->getTitle()
2930                         && $this->getTitle()->isJsSubpage()
2931                         && $this->userCanPreview();
2932         }
2933
2934         private function isUserCssPreview() {
2935                 return $this->getConfig()->get( 'AllowUserCss' )
2936                         && $this->getTitle()
2937                         && $this->getTitle()->isCssSubpage()
2938                         && $this->userCanPreview();
2939         }
2940
2941         /**
2942          * JS stuff to put at the bottom of the `<body>`. These are modules with position 'bottom',
2943          * legacy scripts ($this->mScripts), and user JS.
2944          *
2945          * @return string|WrappedStringList HTML
2946          */
2947         public function getBottomScripts() {
2948                 $chunks = [];
2949                 $chunks[] = $this->getRlClient()->getBodyHtml();
2950
2951                 // Legacy non-ResourceLoader scripts
2952                 $chunks[] = $this->mScripts;
2953
2954                 // Exempt 'user' module
2955                 // - May need excludepages for live preview. (T28283)
2956                 // - Must use TYPE_COMBINED so its response is handled by mw.loader.implement() which
2957                 //   ensures execution is scheduled after the "site" module.
2958                 // - Don't load if module state is already resolved as "ready".
2959                 if ( $this->rlUserModuleState === 'loading' ) {
2960                         if ( $this->isUserJsPreview() ) {
2961                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED,
2962                                         [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
2963                                 );
2964                                 $chunks[] = ResourceLoader::makeInlineScript(
2965                                         Xml::encodeJsCall( 'mw.loader.using', [
2966                                                 [ 'user', 'site' ],
2967                                                 new XmlJsCode(
2968                                                         'function () {'
2969                                                                 . Xml::encodeJsCall( '$.globalEval', [
2970                                                                         $this->getRequest()->getText( 'wpTextbox1' )
2971                                                                 ] )
2972                                                                 . '}'
2973                                                 )
2974                                         ] )
2975                                 );
2976                                 // FIXME: If the user is previewing, say, ./vector.js, his ./common.js will be loaded
2977                                 // asynchronously and may arrive *after* the inline script here. So the previewed code
2978                                 // may execute before ./common.js runs. Normally, ./common.js runs before ./vector.js.
2979                                 // Similarly, when previewing ./common.js and the user module does arrive first,
2980                                 // it will arrive without common.js and the inline script runs after.
2981                                 // Thus running common after the excluded subpage.
2982                         } else {
2983                                 // Load normally
2984                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED );
2985                         }
2986                 }
2987
2988                 return self::combineWrappedStrings( $chunks );
2989         }
2990
2991         /**
2992          * Get the javascript config vars to include on this page
2993          *
2994          * @return array Array of javascript config vars
2995          * @since 1.23
2996          */
2997         public function getJsConfigVars() {
2998                 return $this->mJsConfigVars;
2999         }
3000
3001         /**
3002          * Add one or more variables to be set in mw.config in JavaScript
3003          *
3004          * @param string|array $keys Key or array of key/value pairs
3005          * @param mixed $value [optional] Value of the configuration variable
3006          */
3007         public function addJsConfigVars( $keys, $value = null ) {
3008                 if ( is_array( $keys ) ) {
3009                         foreach ( $keys as $key => $value ) {
3010                                 $this->mJsConfigVars[$key] = $value;
3011                         }
3012                         return;
3013                 }
3014
3015                 $this->mJsConfigVars[$keys] = $value;
3016         }
3017
3018         /**
3019          * Get an array containing the variables to be set in mw.config in JavaScript.
3020          *
3021          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
3022          * - in other words, page-independent/site-wide variables (without state).
3023          * You will only be adding bloat to the html page and causing page caches to
3024          * have to be purged on configuration changes.
3025          * @return array
3026          */
3027         public function getJSVars() {
3028                 global $wgContLang;
3029
3030                 $curRevisionId = 0;
3031                 $articleId = 0;
3032                 $canonicalSpecialPageName = false; # bug 21115
3033
3034                 $title = $this->getTitle();
3035                 $ns = $title->getNamespace();
3036                 $canonicalNamespace = MWNamespace::exists( $ns )
3037                         ? MWNamespace::getCanonicalName( $ns )
3038                         : $title->getNsText();
3039
3040                 $sk = $this->getSkin();
3041                 // Get the relevant title so that AJAX features can use the correct page name
3042                 // when making API requests from certain special pages (bug 34972).
3043                 $relevantTitle = $sk->getRelevantTitle();
3044                 $relevantUser = $sk->getRelevantUser();
3045
3046                 if ( $ns == NS_SPECIAL ) {
3047                         list( $canonicalSpecialPageName, /*...*/ ) =
3048                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3049                 } elseif ( $this->canUseWikiPage() ) {
3050                         $wikiPage = $this->getWikiPage();
3051                         $curRevisionId = $wikiPage->getLatest();
3052                         $articleId = $wikiPage->getId();
3053                 }
3054
3055                 $lang = $title->getPageViewLanguage();
3056
3057                 // Pre-process information
3058                 $separatorTransTable = $lang->separatorTransformTable();
3059                 $separatorTransTable = $separatorTransTable ? $separatorTransTable : [];
3060                 $compactSeparatorTransTable = [
3061                         implode( "\t", array_keys( $separatorTransTable ) ),
3062                         implode( "\t", $separatorTransTable ),
3063                 ];
3064                 $digitTransTable = $lang->digitTransformTable();
3065                 $digitTransTable = $digitTransTable ? $digitTransTable : [];
3066                 $compactDigitTransTable = [
3067                         implode( "\t", array_keys( $digitTransTable ) ),
3068                         implode( "\t", $digitTransTable ),
3069                 ];
3070
3071                 $user = $this->getUser();
3072
3073                 $vars = [
3074                         'wgCanonicalNamespace' => $canonicalNamespace,
3075                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3076                         'wgNamespaceNumber' => $title->getNamespace(),
3077                         'wgPageName' => $title->getPrefixedDBkey(),
3078                         'wgTitle' => $title->getText(),
3079                         'wgCurRevisionId' => $curRevisionId,
3080                         'wgRevisionId' => (int)$this->getRevisionId(),
3081                         'wgArticleId' => $articleId,
3082                         'wgIsArticle' => $this->isArticle(),
3083                         'wgIsRedirect' => $title->isRedirect(),
3084                         'wgAction' => Action::getActionName( $this->getContext() ),
3085                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3086                         'wgUserGroups' => $user->getEffectiveGroups(),
3087                         'wgCategories' => $this->getCategories(),
3088                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3089                         'wgPageContentLanguage' => $lang->getCode(),
3090                         'wgPageContentModel' => $title->getContentModel(),
3091                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3092                         'wgDigitTransformTable' => $compactDigitTransTable,
3093                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3094                         'wgMonthNames' => $lang->getMonthNamesArray(),
3095                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3096                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3097                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3098                         'wgRequestId' => WebRequest::getRequestId(),
3099                 ];
3100
3101                 if ( $user->isLoggedIn() ) {
3102                         $vars['wgUserId'] = $user->getId();
3103                         $vars['wgUserEditCount'] = $user->getEditCount();
3104                         $userReg = $user->getRegistration();
3105                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3106                         // Get the revision ID of the oldest new message on the user's talk
3107                         // page. This can be used for constructing new message alerts on
3108                         // the client side.
3109                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3110                 }
3111
3112                 if ( $wgContLang->hasVariants() ) {
3113                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3114                 }
3115                 // Same test as SkinTemplate
3116                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3117                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3118
3119                 foreach ( $title->getRestrictionTypes() as $type ) {
3120                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3121                 }
3122
3123                 if ( $title->isMainPage() ) {
3124                         $vars['wgIsMainPage'] = true;
3125                 }
3126
3127                 if ( $this->mRedirectedFrom ) {
3128                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3129                 }
3130
3131                 if ( $relevantUser ) {
3132                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3133                 }
3134
3135                 // Allow extensions to add their custom variables to the mw.config map.
3136                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3137                 // page-dependant but site-wide (without state).
3138                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3139                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3140
3141                 // Merge in variables from addJsConfigVars last
3142                 return array_merge( $vars, $this->getJsConfigVars() );
3143         }
3144
3145         /**
3146          * To make it harder for someone to slip a user a fake
3147          * user-JavaScript or user-CSS preview, a random token
3148          * is associated with the login session. If it's not
3149          * passed back with the preview request, we won't render
3150          * the code.
3151          *
3152          * @return bool
3153          */
3154         public function userCanPreview() {
3155                 $request = $this->getRequest();
3156                 if (
3157                         $request->getVal( 'action' ) !== 'submit' ||
3158                         !$request->getCheck( 'wpPreview' ) ||
3159                         !$request->wasPosted()
3160                 ) {
3161                         return false;
3162                 }
3163
3164                 $user = $this->getUser();
3165
3166                 if ( !$user->isLoggedIn() ) {
3167                         // Anons have predictable edit tokens
3168                         return false;
3169                 }
3170                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3171                         return false;
3172                 }
3173
3174                 $title = $this->getTitle();
3175                 if ( !$title->isJsSubpage() && !$title->isCssSubpage() ) {
3176                         return false;
3177                 }
3178                 if ( !$title->isSubpageOf( $user->getUserPage() ) ) {
3179                         // Don't execute another user's CSS or JS on preview (T85855)
3180                         return false;
3181                 }
3182
3183                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3184                 if ( count( $errors ) !== 0 ) {
3185                         return false;
3186                 }
3187
3188                 return true;
3189         }
3190
3191         /**
3192          * @return array Array in format "link name or number => 'link html'".
3193          */
3194         public function getHeadLinksArray() {
3195                 global $wgVersion;
3196
3197                 $tags = [];
3198                 $config = $this->getConfig();
3199
3200                 $canonicalUrl = $this->mCanonicalUrl;
3201
3202                 $tags['meta-generator'] = Html::element( 'meta', [
3203                         'name' => 'generator',
3204                         'content' => "MediaWiki $wgVersion",
3205                 ] );
3206
3207                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3208                         $tags['meta-referrer'] = Html::element( 'meta', [
3209                                 'name' => 'referrer',
3210                                 'content' => $config->get( 'ReferrerPolicy' )
3211                         ] );
3212                 }
3213
3214                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3215                 if ( $p !== 'index,follow' ) {
3216                         // http://www.robotstxt.org/wc/meta-user.html
3217                         // Only show if it's different from the default robots policy
3218                         $tags['meta-robots'] = Html::element( 'meta', [
3219                                 'name' => 'robots',
3220                                 'content' => $p,
3221                         ] );
3222                 }
3223
3224                 foreach ( $this->mMetatags as $tag ) {
3225                         if ( 0 == strcasecmp( 'http:', substr( $tag[0], 0, 5 ) ) ) {
3226                                 $a = 'http-equiv';
3227                                 $tag[0] = substr( $tag[0], 5 );
3228                         } else {
3229                                 $a = 'name';
3230                         }
3231                         $tagName = "meta-{$tag[0]}";
3232                         if ( isset( $tags[$tagName] ) ) {
3233                                 $tagName .= $tag[1];
3234                         }
3235                         $tags[$tagName] = Html::element( 'meta',
3236                                 [
3237                                         $a => $tag[0],
3238                                         'content' => $tag[1]
3239                                 ]
3240                         );
3241                 }
3242
3243                 foreach ( $this->mLinktags as $tag ) {
3244                         $tags[] = Html::element( 'link', $tag );
3245                 }
3246
3247                 # Universal edit button
3248                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3249                         $user = $this->getUser();
3250                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3251                                 && ( $this->getTitle()->exists() ||
3252                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3253                         ) {
3254                                 // Original UniversalEditButton
3255                                 $msg = $this->msg( 'edit' )->text();
3256                                 $tags['universal-edit-button'] = Html::element( 'link', [
3257                                         'rel' => 'alternate',
3258                                         'type' => 'application/x-wiki',
3259                                         'title' => $msg,
3260                                         'href' => $this->getTitle()->getEditURL(),
3261                                 ] );
3262                                 // Alternate edit link
3263                                 $tags['alternative-edit'] = Html::element( 'link', [
3264                                         'rel' => 'edit',
3265                                         'title' => $msg,
3266                                         'href' => $this->getTitle()->getEditURL(),
3267                                 ] );
3268                         }
3269                 }
3270
3271                 # Generally the order of the favicon and apple-touch-icon links
3272                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3273                 # uses whichever one appears later in the HTML source. Make sure
3274                 # apple-touch-icon is specified first to avoid this.
3275                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3276                         $tags['apple-touch-icon'] = Html::element( 'link', [
3277                                 'rel' => 'apple-touch-icon',
3278                                 'href' => $config->get( 'AppleTouchIcon' )
3279                         ] );
3280                 }
3281
3282                 if ( $config->get( 'Favicon' ) !== false ) {
3283                         $tags['favicon'] = Html::element( 'link', [
3284                                 'rel' => 'shortcut icon',
3285                                 'href' => $config->get( 'Favicon' )
3286                         ] );
3287                 }
3288
3289                 # OpenSearch description link
3290                 $tags['opensearch'] = Html::element( 'link', [
3291                         'rel' => 'search',
3292                         'type' => 'application/opensearchdescription+xml',
3293                         'href' => wfScript( 'opensearch_desc' ),
3294                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3295                 ] );
3296
3297                 if ( $config->get( 'EnableAPI' ) ) {
3298                         # Real Simple Discovery link, provides auto-discovery information
3299                         # for the MediaWiki API (and potentially additional custom API
3300                         # support such as WordPress or Twitter-compatible APIs for a
3301                         # blogging extension, etc)
3302                         $tags['rsd'] = Html::element( 'link', [
3303                                 'rel' => 'EditURI',
3304                                 'type' => 'application/rsd+xml',
3305                                 // Output a protocol-relative URL here if $wgServer is protocol-relative.
3306                                 // Whether RSD accepts relative or protocol-relative URLs is completely
3307                                 // undocumented, though.
3308                                 'href' => wfExpandUrl( wfAppendQuery(
3309                                         wfScript( 'api' ),
3310                                         [ 'action' => 'rsd' ] ),
3311                                         PROTO_RELATIVE
3312                                 ),
3313                         ] );
3314                 }
3315
3316                 # Language variants
3317                 if ( !$config->get( 'DisableLangConversion' ) ) {
3318                         $lang = $this->getTitle()->getPageLanguage();
3319                         if ( $lang->hasVariants() ) {
3320                                 $variants = $lang->getVariants();
3321                                 foreach ( $variants as $variant ) {
3322                                         $tags["variant-$variant"] = Html::element( 'link', [
3323                                                 'rel' => 'alternate',
3324                                                 'hreflang' => wfBCP47( $variant ),
3325                                                 'href' => $this->getTitle()->getLocalURL(
3326                                                         [ 'variant' => $variant ] )
3327                                                 ]
3328                                         );
3329                                 }
3330                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3331                                 $tags["variant-x-default"] = Html::element( 'link', [
3332                                         'rel' => 'alternate',
3333                                         'hreflang' => 'x-default',
3334                                         'href' => $this->getTitle()->getLocalURL() ] );
3335                         }
3336                 }
3337
3338                 # Copyright
3339                 if ( $this->copyrightUrl !== null ) {
3340                         $copyright = $this->copyrightUrl;
3341                 } else {
3342                         $copyright = '';
3343                         if ( $config->get( 'RightsPage' ) ) {
3344                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3345
3346                                 if ( $copy ) {
3347                                         $copyright = $copy->getLocalURL();
3348                                 }
3349                         }
3350
3351                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3352                                 $copyright = $config->get( 'RightsUrl' );
3353                         }
3354                 }
3355
3356                 if ( $copyright ) {
3357                         $tags['copyright'] = Html::element( 'link', [
3358                                 'rel' => 'copyright',
3359                                 'href' => $copyright ]
3360                         );
3361                 }
3362
3363                 # Feeds
3364                 if ( $config->get( 'Feed' ) ) {
3365                         $feedLinks = [];
3366
3367                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3368                                 # Use the page name for the title.  In principle, this could
3369                                 # lead to issues with having the same name for different feeds
3370                                 # corresponding to the same page, but we can't avoid that at
3371                                 # this low a level.
3372
3373                                 $feedLinks[] = $this->feedLink(
3374                                         $format,
3375                                         $link,
3376                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3377                                         $this->msg(
3378                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3379                                         )->text()
3380                                 );
3381                         }
3382
3383                         # Recent changes feed should appear on every page (except recentchanges,
3384                         # that would be redundant). Put it after the per-page feed to avoid
3385                         # changing existing behavior. It's still available, probably via a
3386                         # menu in your browser. Some sites might have a different feed they'd
3387                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3388                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3389                         # If so, use it instead.
3390                         $sitename = $config->get( 'Sitename' );
3391                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3392                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3393                                         // Note, this->feedLink escapes the url.
3394                                         $feedLinks[] = $this->feedLink(
3395                                                 $type,
3396                                                 $feedUrl,
3397                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3398                                         );
3399                                 }
3400                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3401                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3402                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3403                                         $feedLinks[] = $this->feedLink(
3404                                                 $format,
3405                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3406                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3407                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3408                                         );
3409                                 }
3410                         }
3411
3412                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3413                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3414                         # use OutputPage::addFeedLink() instead.
3415                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3416
3417                         $tags += $feedLinks;
3418                 }
3419
3420                 # Canonical URL
3421                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3422                         if ( $canonicalUrl !== false ) {
3423                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3424                         } else {
3425                                 if ( $this->isArticleRelated() ) {
3426                                         // This affects all requests where "setArticleRelated" is true. This is
3427                                         // typically all requests that show content (query title, curid, oldid, diff),
3428                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3429                                         // It does not apply to File pages and Special pages.
3430                                         // 'history' and 'info' actions address page metadata rather than the page
3431                                         // content itself, so they may not be canonicalized to the view page url.
3432                                         // TODO: this ought to be better encapsulated in the Action class.
3433                                         $action = Action::getActionName( $this->getContext() );
3434                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3435                                                 $query = "action={$action}";
3436                                         } else {
3437                                                 $query = '';
3438                                         }
3439                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3440                                 } else {
3441                                         $reqUrl = $this->getRequest()->getRequestURL();
3442                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3443                                 }
3444                         }
3445                 }
3446                 if ( $canonicalUrl !== false ) {
3447                         $tags[] = Html::element( 'link', [
3448                                 'rel' => 'canonical',
3449                                 'href' => $canonicalUrl
3450                         ] );
3451                 }
3452
3453                 return $tags;
3454         }
3455
3456         /**
3457          * @return string HTML tag links to be put in the header.
3458          * @deprecated since 1.24 Use OutputPage::headElement or if you have to,
3459          *   OutputPage::getHeadLinksArray directly.
3460          */
3461         public function getHeadLinks() {
3462                 wfDeprecated( __METHOD__, '1.24' );
3463                 return implode( "\n", $this->getHeadLinksArray() );
3464         }
3465
3466         /**
3467          * Generate a "<link rel/>" for a feed.
3468          *
3469          * @param string $type Feed type
3470          * @param string $url URL to the feed
3471          * @param string $text Value of the "title" attribute
3472          * @return string HTML fragment
3473          */
3474         private function feedLink( $type, $url, $text ) {
3475                 return Html::element( 'link', [
3476                         'rel' => 'alternate',
3477                         'type' => "application/$type+xml",
3478                         'title' => $text,
3479                         'href' => $url ]
3480                 );
3481         }
3482
3483         /**
3484          * Add a local or specified stylesheet, with the given media options.
3485          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3486          *
3487          * @param string $style URL to the file
3488          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3489          * @param string $condition For IE conditional comments, specifying an IE version
3490          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3491          */
3492         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3493                 $options = [];
3494                 if ( $media ) {
3495                         $options['media'] = $media;
3496                 }
3497                 if ( $condition ) {
3498                         $options['condition'] = $condition;
3499                 }
3500                 if ( $dir ) {
3501                         $options['dir'] = $dir;
3502                 }
3503                 $this->styles[$style] = $options;
3504         }
3505
3506         /**
3507          * Adds inline CSS styles
3508          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3509          *
3510          * @param mixed $style_css Inline CSS
3511          * @param string $flip Set to 'flip' to flip the CSS if needed
3512          */
3513         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3514                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3515                         # If wanted, and the interface is right-to-left, flip the CSS
3516                         $style_css = CSSJanus::transform( $style_css, true, false );
3517                 }
3518                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3519         }
3520
3521         /**
3522          * Build exempt modules and legacy non-ResourceLoader styles.
3523          *
3524          * @return string|WrappedStringList HTML
3525          */
3526         protected function buildExemptModules() {
3527                 global $wgContLang;
3528
3529                 $resourceLoader = $this->getResourceLoader();
3530                 $chunks = [];
3531                 // Things that go after the ResourceLoaderDynamicStyles marker
3532                 $append = [];
3533
3534                 // Exempt 'user' styles module (may need 'excludepages' for live preview)
3535                 if ( $this->isUserCssPreview() ) {
3536                         $append[] = $this->makeResourceLoaderLink(
3537                                 'user.styles',
3538                                 ResourceLoaderModule::TYPE_STYLES,
3539                                 [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
3540                         );
3541
3542                         // Load the previewed CSS. Janus it if needed.
3543                         // User-supplied CSS is assumed to in the wiki's content language.
3544                         $previewedCSS = $this->getRequest()->getText( 'wpTextbox1' );
3545                         if ( $this->getLanguage()->getDir() !== $wgContLang->getDir() ) {
3546                                 $previewedCSS = CSSJanus::transform( $previewedCSS, true, false );
3547                         }
3548                         $append[] = Html::inlineStyle( $previewedCSS );
3549                 }
3550
3551                 // We want site, private and user styles to override dynamically added styles from
3552                 // general modules, but we want dynamically added styles to override statically added
3553                 // style modules. So the order has to be:
3554                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3555                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3556                 // - ResourceLoaderDynamicStyles marker
3557                 // - site/private/user styles
3558
3559                 // Add legacy styles added through addStyle()/addInlineStyle() here
3560                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3561
3562                 $chunks[] = Html::element(
3563                         'meta',
3564                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3565                 );
3566
3567                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3568                         $chunks[] = $this->makeResourceLoaderLink( $moduleNames,
3569                                 ResourceLoaderModule::TYPE_STYLES
3570                         );
3571                 }
3572
3573                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3574         }
3575
3576         /**
3577          * @return array
3578          */
3579         public function buildCssLinksArray() {
3580                 $links = [];
3581
3582                 // Add any extension CSS
3583                 foreach ( $this->mExtStyles as $url ) {
3584                         $this->addStyle( $url );
3585                 }
3586                 $this->mExtStyles = [];
3587
3588                 foreach ( $this->styles as $file => $options ) {
3589                         $link = $this->styleLink( $file, $options );
3590                         if ( $link ) {
3591                                 $links[$file] = $link;
3592                         }
3593                 }
3594                 return $links;
3595         }
3596
3597         /**
3598          * Generate \<link\> tags for stylesheets
3599          *
3600          * @param string $style URL to the file
3601          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3602          * @return string HTML fragment
3603          */
3604         protected function styleLink( $style, array $options ) {
3605                 if ( isset( $options['dir'] ) ) {
3606                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3607                                 return '';
3608                         }
3609                 }
3610
3611                 if ( isset( $options['media'] ) ) {
3612                         $media = self::transformCssMedia( $options['media'] );
3613                         if ( is_null( $media ) ) {
3614                                 return '';
3615                         }
3616                 } else {
3617                         $media = 'all';
3618                 }
3619
3620                 if ( substr( $style, 0, 1 ) == '/' ||
3621                         substr( $style, 0, 5 ) == 'http:' ||
3622                         substr( $style, 0, 6 ) == 'https:' ) {
3623                         $url = $style;
3624                 } else {
3625                         $config = $this->getConfig();
3626                         $url = $config->get( 'StylePath' ) . '/' . $style . '?' .
3627                                 $config->get( 'StyleVersion' );
3628                 }
3629
3630                 $link = Html::linkedStyle( $url, $media );
3631
3632                 if ( isset( $options['condition'] ) ) {
3633                         $condition = htmlspecialchars( $options['condition'] );
3634                         $link = "<!--[if $condition]>$link<![endif]-->";
3635                 }
3636                 return $link;
3637         }
3638
3639         /**
3640          * Transform path to web-accessible static resource.
3641          *
3642          * This is used to add a validation hash as query string.
3643          * This aids various behaviors:
3644          *
3645          * - Put long Cache-Control max-age headers on responses for improved
3646          *   cache performance.
3647          * - Get the correct version of a file as expected by the current page.
3648          * - Instantly get the updated version of a file after deployment.
3649          *
3650          * Avoid using this for urls included in HTML as otherwise clients may get different
3651          * versions of a resource when navigating the site depending on when the page was cached.
3652          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3653          * an external stylesheet).
3654          *
3655          * @since 1.27
3656          * @param Config $config
3657          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3658          * @return string URL
3659          */
3660         public static function transformResourcePath( Config $config, $path ) {
3661                 global $IP;
3662                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3663                 if ( $remotePathPrefix === '' ) {
3664                         // The configured base path is required to be empty string for
3665                         // wikis in the domain root
3666                         $remotePath = '/';
3667                 } else {
3668                         $remotePath = $remotePathPrefix;
3669                 }
3670                 if ( strpos( $path, $remotePath ) !== 0 ) {
3671                         // Path is outside wgResourceBasePath, ignore.
3672                         return $path;
3673                 }
3674                 $path = RelPath\getRelativePath( $path, $remotePath );
3675                 return self::transformFilePath( $remotePathPrefix, $IP, $path );
3676         }
3677
3678         /**
3679          * Utility method for transformResourceFilePath().
3680          *
3681          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3682          *
3683          * @since 1.27
3684          * @param string $remotePath URL path prefix that points to $localPath
3685          * @param string $localPath File directory exposed at $remotePath
3686          * @param string $file Path to target file relative to $localPath
3687          * @return string URL
3688          */
3689         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3690                 $hash = md5_file( "$localPath/$file" );
3691                 if ( $hash === false ) {
3692                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3693                         $hash = '';
3694                 }
3695                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3696         }
3697
3698         /**
3699          * Transform "media" attribute based on request parameters
3700          *
3701          * @param string $media Current value of the "media" attribute
3702          * @return string Modified value of the "media" attribute, or null to skip
3703          * this stylesheet
3704          */
3705         public static function transformCssMedia( $media ) {
3706                 global $wgRequest;
3707
3708                 // https://www.w3.org/TR/css3-mediaqueries/#syntax
3709                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3710
3711                 // Switch in on-screen display for media testing
3712                 $switches = [
3713                         'printable' => 'print',
3714                         'handheld' => 'handheld',
3715                 ];
3716                 foreach ( $switches as $switch => $targetMedia ) {
3717                         if ( $wgRequest->getBool( $switch ) ) {
3718                                 if ( $media == $targetMedia ) {
3719                                         $media = '';
3720                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3721                                         /* This regex will not attempt to understand a comma-separated media_query_list
3722                                          *
3723                                          * Example supported values for $media:
3724                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3725                                          * Example NOT supported value for $media:
3726                                          * '3d-glasses, screen, print and resolution > 90dpi'
3727                                          *
3728                                          * If it's a print request, we never want any kind of screen stylesheets
3729                                          * If it's a handheld request (currently the only other choice with a switch),
3730                                          * we don't want simple 'screen' but we might want screen queries that
3731                                          * have a max-width or something, so we'll pass all others on and let the
3732                                          * client do the query.
3733                                          */
3734                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3735                                                 return null;
3736                                         }
3737                                 }
3738                         }
3739                 }
3740
3741                 return $media;
3742         }
3743
3744         /**
3745          * Add a wikitext-formatted message to the output.
3746          * This is equivalent to:
3747          *
3748          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3749          */
3750         public function addWikiMsg( /*...*/ ) {
3751                 $args = func_get_args();
3752                 $name = array_shift( $args );
3753                 $this->addWikiMsgArray( $name, $args );
3754         }
3755
3756         /**
3757          * Add a wikitext-formatted message to the output.
3758          * Like addWikiMsg() except the parameters are taken as an array
3759          * instead of a variable argument list.
3760          *
3761          * @param string $name
3762          * @param array $args
3763          */
3764         public function addWikiMsgArray( $name, $args ) {
3765                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3766         }
3767
3768         /**
3769          * This function takes a number of message/argument specifications, wraps them in
3770          * some overall structure, and then parses the result and adds it to the output.
3771          *
3772          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3773          * and so on. The subsequent arguments may be either
3774          * 1) strings, in which case they are message names, or
3775          * 2) arrays, in which case, within each array, the first element is the message
3776          *    name, and subsequent elements are the parameters to that message.
3777          *
3778          * Don't use this for messages that are not in the user's interface language.
3779          *
3780          * For example:
3781          *
3782          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3783          *
3784          * Is equivalent to:
3785          *
3786          *    $wgOut->addWikiText( "<div class='error'>\n"
3787          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3788          *
3789          * The newline after the opening div is needed in some wikitext. See bug 19226.
3790          *
3791          * @param string $wrap
3792          */
3793         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3794                 $msgSpecs = func_get_args();
3795                 array_shift( $msgSpecs );
3796                 $msgSpecs = array_values( $msgSpecs );
3797                 $s = $wrap;
3798                 foreach ( $msgSpecs as $n => $spec ) {
3799                         if ( is_array( $spec ) ) {
3800                                 $args = $spec;
3801                                 $name = array_shift( $args );
3802                                 if ( isset( $args['options'] ) ) {
3803                                         unset( $args['options'] );
3804                                         wfDeprecated(
3805                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3806                                                 '1.20'
3807                                         );
3808                                 }
3809                         } else {
3810                                 $args = [];
3811                                 $name = $spec;
3812                         }
3813                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3814                 }
3815                 $this->addWikiText( $s );
3816         }
3817
3818         /**
3819          * Enables/disables TOC, doesn't override __NOTOC__
3820          * @param bool $flag
3821          * @since 1.22
3822          */
3823         public function enableTOC( $flag = true ) {
3824                 $this->mEnableTOC = $flag;
3825         }
3826
3827         /**
3828          * @return bool
3829          * @since 1.22
3830          */
3831         public function isTOCEnabled() {
3832                 return $this->mEnableTOC;
3833         }
3834
3835         /**
3836          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3837          * @param bool $flag
3838          * @since 1.23
3839          */
3840         public function enableSectionEditLinks( $flag = true ) {
3841                 $this->mEnableSectionEditLinks = $flag;
3842         }
3843
3844         /**
3845          * @return bool
3846          * @since 1.23
3847          */
3848         public function sectionEditLinksEnabled() {
3849                 return $this->mEnableSectionEditLinks;
3850         }
3851
3852         /**
3853          * Helper function to setup the PHP implementation of OOUI to use in this request.
3854          *
3855          * @since 1.26
3856          * @param String $skinName The Skin name to determine the correct OOUI theme
3857          * @param String $dir Language direction
3858          */
3859         public static function setupOOUI( $skinName = '', $dir = 'ltr' ) {
3860                 $themes = ExtensionRegistry::getInstance()->getAttribute( 'SkinOOUIThemes' );
3861                 // Make keys (skin names) lowercase for case-insensitive matching.
3862                 $themes = array_change_key_case( $themes, CASE_LOWER );
3863                 $theme = isset( $themes[$skinName] ) ? $themes[$skinName] : 'MediaWiki';
3864                 // For example, 'OOUI\MediaWikiTheme'.
3865                 $themeClass = "OOUI\\{$theme}Theme";
3866                 OOUI\Theme::setSingleton( new $themeClass() );
3867                 OOUI\Element::setDefaultDir( $dir );
3868         }
3869
3870         /**
3871          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3872          * MediaWiki and this OutputPage instance.
3873          *
3874          * @since 1.25
3875          */
3876         public function enableOOUI() {
3877                 self::setupOOUI(
3878                         strtolower( $this->getSkin()->getSkinName() ),
3879                         $this->getLanguage()->getDir()
3880                 );
3881                 $this->addModuleStyles( [
3882                         'oojs-ui-core.styles',
3883                         'oojs-ui.styles.icons',
3884                         'oojs-ui.styles.indicators',
3885                         'oojs-ui.styles.textures',
3886                         'mediawiki.widgets.styles',
3887                 ] );
3888         }
3889 }