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
 112         /** @var array */
 113         protected $mIndicators = [];
 114
 115         /** @var array Array of Interwiki Prefixed (non DB key) Titles (e.g. 'fr:Test page') */
 116         private $mLanguageLinks = [];
 117
 118         /**
 119          * Used for JavaScript (predates ResourceLoader)
 120          * @todo We should split JS / CSS.
 121          * mScripts content is inserted as is in "<head>" by Skin. This might
 122          * contain either a link to a stylesheet or inline CSS.
 123          */
 124         private $mScripts = '';
 125
 126         /** @var string Inline CSS styles. Use addInlineStyle() sparingly */
 127         protected $mInlineStyles = '';
 128
 129         /**
 130          * @var string Used by skin template.
 131          * Example: $tpl->set( 'displaytitle', $out->mPageLinkTitle );
 132          */
 133         public $mPageLinkTitle = '';
 134
 135         /** @var array Array of elements in "<head>". Parser might add its own headers! */
 136         protected $mHeadItems = [];
 137
 138         /** @var array */
 139         protected $mModules = [];
 140
 141         /** @var array */
 142         protected $mModuleScripts = [];
 143
 144         /** @var array */
 145         protected $mModuleStyles = [];
 146
 147         /** @var ResourceLoader */
 148         protected $mResourceLoader;
 149
 150         /** @var ResourceLoaderClientHtml */
 151         private $rlClient;
 152
 153         /** @var ResourceLoaderContext */
 154         private $rlClientContext;
 155
 156         /** @var string */
 157         private $rlUserModuleState;
 158
 159         /** @var array */
 160         private $rlExemptStyleModules;
 161
 162         /** @var array */
 163         protected $mJsConfigVars = [];
 164
 165         /** @var array */
 166         protected $mTemplateIds = [];
 167
 168         /** @var array */
 169         protected $mImageTimeKeys = [];
 170
 171         /** @var string */
 172         public $mRedirectCode = '';
 173
 174         protected $mFeedLinksAppendQuery = null;
 175
 176         /** @var array
 177          * What level of 'untrustworthiness' is allowed in CSS/JS modules loaded on this page?
 178          * @see ResourceLoaderModule::$origin
 179          * ResourceLoaderModule::ORIGIN_ALL is assumed unless overridden;
 180          */
 181         protected $mAllowedModules = [
 182                 ResourceLoaderModule::TYPE_COMBINED => ResourceLoaderModule::ORIGIN_ALL,
 183         ];
 184
 185         /** @var bool Whether output is disabled.  If this is true, the 'output' method will do nothing. */
 186         protected $mDoNothing = false;
 187
 188         // Parser related.
 189
 190         /** @var int */
 191         protected $mContainsNewMagic = 0;
 192
 193         /**
 194          * lazy initialised, use parserOptions()
 195          * @var ParserOptions
 196          */
 197         protected $mParserOptions = null;
 198
 199         /**
 200          * Handles the Atom / RSS links.
 201          * We probably only support Atom in 2011.
 202          * @see $wgAdvertisedFeedTypes
 203          */
 204         private $mFeedLinks = [];
 205
 206         // Gwicke work on squid caching? Roughly from 2003.
 207         protected $mEnableClientCache = true;
 208
 209         /** @var bool Flag if output should only contain the body of the article. */
 210         private $mArticleBodyOnly = false;
 211
 212         /** @var bool */
 213         protected $mNewSectionLink = false;
 214
 215         /** @var bool */
 216         protected $mHideNewSectionLink = false;
 217
 218         /**
 219          * @var bool Comes from the parser. This was probably made to load CSS/JS
 220          * only if we had "<gallery>". Used directly in CategoryPage.php.
 221          * Looks like ResourceLoader can replace this.
 222          */
 223         public $mNoGallery = false;
 224
 225         /** @var string */
 226         private $mPageTitleActionText = '';
 227
 228         /** @var int Cache stuff. Looks like mEnableClientCache */
 229         protected $mCdnMaxage = 0;
 230         /** @var int Upper limit on mCdnMaxage */
 231         protected $mCdnMaxageLimit = INF;
 232
 233         /**
 234          * @var bool Controls if anti-clickjacking / frame-breaking headers will
 235          * be sent. This should be done for pages where edit actions are possible.
 236          * Setters: $this->preventClickjacking() and $this->allowClickjacking().
 237          */
 238         protected $mPreventClickjacking = true;
 239
 240         /** @var int To include the variable {{REVISIONID}} */
 241         private $mRevisionId = null;
 242
 243         /** @var string */
 244         private $mRevisionTimestamp = null;
 245
 246         /** @var array */
 247         protected $mFileVersion = null;
 248
 249         /**
 250          * @var array An array of stylesheet filenames (relative from skins path),
 251          * with options for CSS media, IE conditions, and RTL/LTR direction.
 252          * For internal use; add settings in the skin via $this->addStyle()
 253          *
 254          * Style again! This seems like a code duplication since we already have
 255          * mStyles. This is what makes Open Source amazing.
 256          */
 257         protected $styles = [];
 258
 259         private $mIndexPolicy = 'index';
 260         private $mFollowPolicy = 'follow';
 261         private $mVaryHeader = [
 262                 'Accept-Encoding' => [ 'match=gzip' ],
 263         ];
 264
 265         /**
 266          * If the current page was reached through a redirect, $mRedirectedFrom contains the Title
 267          * of the redirect.
 268          *
 269          * @var Title
 270          */
 271         private $mRedirectedFrom = null;
 272
 273         /**
 274          * Additional key => value data
 275          */
 276         private $mProperties = [];
 277
 278         /**
 279          * @var string|null ResourceLoader target for load.php links. If null, will be omitted
 280          */
 281         private $mTarget = null;
 282
 283         /**
 284          * @var bool Whether parser output should contain table of contents
 285          */
 286         private $mEnableTOC = true;
 287
 288         /**
 289          * @var bool Whether parser output should contain section edit links
 290          */
 291         private $mEnableSectionEditLinks = true;
 292
 293         /**
 294          * @var string|null The URL to send in a <link> element with rel=copyright
 295          */
 296         private $copyrightUrl;
 297
 298         /** @var array Profiling data */
 299         private $limitReportData = [];
 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 array $newLinkArray Associative array mapping language code to the page
1218          *                      name
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 array $newLinkArray Associative array mapping language code to the page
1228          *                      name
1229          */
1230         public function setLanguageLinks( array $newLinkArray ) {
1231                 $this->mLanguageLinks = $newLinkArray;
1232         }
1233
1234         /**
1235          * Get the list of language links
1236          *
1237          * @return array 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                 # Add the links to a LinkBatch
1256                 $arr = [ NS_CATEGORY => $categories ];
1257                 $lb = new LinkBatch;
1258                 $lb->setArray( $arr );
1259
1260                 # Fetch existence plus the hiddencat property
1261                 $dbr = wfGetDB( DB_REPLICA );
1262                 $fields = array_merge(
1263                         LinkCache::getSelectFields(),
1264                         [ 'page_namespace', 'page_title', 'pp_value' ]
1265                 );
1266
1267                 $res = $dbr->select( [ 'page', 'page_props' ],
1268                         $fields,
1269                         $lb->constructSet( 'page', $dbr ),
1270                         __METHOD__,
1271                         [],
1272                         [ 'page_props' => [ 'LEFT JOIN', [
1273                                 'pp_propname' => 'hiddencat',
1274                                 'pp_page = page_id'
1275                         ] ] ]
1276                 );
1277
1278                 # Add the results to the link cache
1279                 $lb->addResultToCache( LinkCache::singleton(), $res );
1280
1281                 # Set all the values to 'normal'.
1282                 $categories = array_fill_keys( array_keys( $categories ), 'normal' );
1283
1284                 # Mark hidden categories
1285                 foreach ( $res as $row ) {
1286                         if ( isset( $row->pp_value ) ) {
1287                                 $categories[$row->page_title] = 'hidden';
1288                         }
1289                 }
1290
1291                 # Add the remaining categories to the skin
1292                 if ( Hooks::run(
1293                         'OutputPageMakeCategoryLinks',
1294                         [ &$this, $categories, &$this->mCategoryLinks ] )
1295                 ) {
1296                         foreach ( $categories as $category => $type ) {
1297                                 // array keys will cast numeric category names to ints, so cast back to string
1298                                 $category = (string)$category;
1299                                 $origcategory = $category;
1300                                 $title = Title::makeTitleSafe( NS_CATEGORY, $category );
1301                                 if ( !$title ) {
1302                                         continue;
1303                                 }
1304                                 $wgContLang->findVariantLink( $category, $title, true );
1305                                 if ( $category != $origcategory && array_key_exists( $category, $categories ) ) {
1306                                         continue;
1307                                 }
1308                                 $text = $wgContLang->convertHtml( $title->getText() );
1309                                 $this->mCategories[] = $title->getText();
1310                                 $this->mCategoryLinks[$type][] = Linker::link( $title, $text );
1311                         }
1312                 }
1313         }
1314
1315         /**
1316          * Reset the category links (but not the category list) and add $categories
1317          *
1318          * @param array $categories Mapping category name => sort key
1319          */
1320         public function setCategoryLinks( array $categories ) {
1321                 $this->mCategoryLinks = [];
1322                 $this->addCategoryLinks( $categories );
1323         }
1324
1325         /**
1326          * Get the list of category links, in a 2-D array with the following format:
1327          * $arr[$type][] = $link, where $type is either "normal" or "hidden" (for
1328          * hidden categories) and $link a HTML fragment with a link to the category
1329          * page
1330          *
1331          * @return array
1332          */
1333         public function getCategoryLinks() {
1334                 return $this->mCategoryLinks;
1335         }
1336
1337         /**
1338          * Get the list of category names this page belongs to
1339          *
1340          * @return array Array of strings
1341          */
1342         public function getCategories() {
1343                 return $this->mCategories;
1344         }
1345
1346         /**
1347          * Add an array of indicators, with their identifiers as array
1348          * keys and HTML contents as values.
1349          *
1350          * In case of duplicate keys, existing values are overwritten.
1351          *
1352          * @param array $indicators
1353          * @since 1.25
1354          */
1355         public function setIndicators( array $indicators ) {
1356                 $this->mIndicators = $indicators + $this->mIndicators;
1357                 // Keep ordered by key
1358                 ksort( $this->mIndicators );
1359         }
1360
1361         /**
1362          * Get the indicators associated with this page.
1363          *
1364          * The array will be internally ordered by item keys.
1365          *
1366          * @return array Keys: identifiers, values: HTML contents
1367          * @since 1.25
1368          */
1369         public function getIndicators() {
1370                 return $this->mIndicators;
1371         }
1372
1373         /**
1374          * Adds help link with an icon via page indicators.
1375          * Link target can be overridden by a local message containing a wikilink:
1376          * the message key is: lowercase action or special page name + '-helppage'.
1377          * @param string $to Target MediaWiki.org page title or encoded URL.
1378          * @param bool $overrideBaseUrl Whether $url is a full URL, to avoid MW.o.
1379          * @since 1.25
1380          */
1381         public function addHelpLink( $to, $overrideBaseUrl = false ) {
1382                 $this->addModuleStyles( 'mediawiki.helplink' );
1383                 $text = $this->msg( 'helppage-top-gethelp' )->escaped();
1384
1385                 if ( $overrideBaseUrl ) {
1386                         $helpUrl = $to;
1387                 } else {
1388                         $toUrlencoded = wfUrlencode( str_replace( ' ', '_', $to ) );
1389                         $helpUrl = "//www.mediawiki.org/wiki/Special:MyLanguage/$toUrlencoded";
1390                 }
1391
1392                 $link = Html::rawElement(
1393                         'a',
1394                         [
1395                                 'href' => $helpUrl,
1396                                 'target' => '_blank',
1397                                 'class' => 'mw-helplink',
1398                         ],
1399                         $text
1400                 );
1401
1402                 $this->setIndicators( [ 'mw-helplink' => $link ] );
1403         }
1404
1405         /**
1406          * Do not allow scripts which can be modified by wiki users to load on this page;
1407          * only allow scripts bundled with, or generated by, the software.
1408          * Site-wide styles are controlled by a config setting, since they can be
1409          * used to create a custom skin/theme, but not user-specific ones.
1410          *
1411          * @todo this should be given a more accurate name
1412          */
1413         public function disallowUserJs() {
1414                 $this->reduceAllowedModules(
1415                         ResourceLoaderModule::TYPE_SCRIPTS,
1416                         ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL
1417                 );
1418
1419                 // Site-wide styles are controlled by a config setting, see bug 71621
1420                 // for background on why. User styles are never allowed.
1421                 if ( $this->getConfig()->get( 'AllowSiteCSSOnRestrictedPages' ) ) {
1422                         $styleOrigin = ResourceLoaderModule::ORIGIN_USER_SITEWIDE;
1423                 } else {
1424                         $styleOrigin = ResourceLoaderModule::ORIGIN_CORE_INDIVIDUAL;
1425                 }
1426                 $this->reduceAllowedModules(
1427                         ResourceLoaderModule::TYPE_STYLES,
1428                         $styleOrigin
1429                 );
1430         }
1431
1432         /**
1433          * Show what level of JavaScript / CSS untrustworthiness is allowed on this page
1434          * @see ResourceLoaderModule::$origin
1435          * @param string $type ResourceLoaderModule TYPE_ constant
1436          * @return int ResourceLoaderModule ORIGIN_ class constant
1437          */
1438         public function getAllowedModules( $type ) {
1439                 if ( $type == ResourceLoaderModule::TYPE_COMBINED ) {
1440                         return min( array_values( $this->mAllowedModules ) );
1441                 } else {
1442                         return isset( $this->mAllowedModules[$type] )
1443                                 ? $this->mAllowedModules[$type]
1444                                 : ResourceLoaderModule::ORIGIN_ALL;
1445                 }
1446         }
1447
1448         /**
1449          * Limit the highest level of CSS/JS untrustworthiness allowed.
1450          *
1451          * If passed the same or a higher level than the current level of untrustworthiness set, the
1452          * level will remain unchanged.
1453          *
1454          * @param string $type
1455          * @param int $level ResourceLoaderModule class constant
1456          */
1457         public function reduceAllowedModules( $type, $level ) {
1458                 $this->mAllowedModules[$type] = min( $this->getAllowedModules( $type ), $level );
1459         }
1460
1461         /**
1462          * Prepend $text to the body HTML
1463          *
1464          * @param string $text HTML
1465          */
1466         public function prependHTML( $text ) {
1467                 $this->mBodytext = $text . $this->mBodytext;
1468         }
1469
1470         /**
1471          * Append $text to the body HTML
1472          *
1473          * @param string $text HTML
1474          */
1475         public function addHTML( $text ) {
1476                 $this->mBodytext .= $text;
1477         }
1478
1479         /**
1480          * Shortcut for adding an Html::element via addHTML.
1481          *
1482          * @since 1.19
1483          *
1484          * @param string $element
1485          * @param array $attribs
1486          * @param string $contents
1487          */
1488         public function addElement( $element, array $attribs = [], $contents = '' ) {
1489                 $this->addHTML( Html::element( $element, $attribs, $contents ) );
1490         }
1491
1492         /**
1493          * Clear the body HTML
1494          */
1495         public function clearHTML() {
1496                 $this->mBodytext = '';
1497         }
1498
1499         /**
1500          * Get the body HTML
1501          *
1502          * @return string HTML
1503          */
1504         public function getHTML() {
1505                 return $this->mBodytext;
1506         }
1507
1508         /**
1509          * Get/set the ParserOptions object to use for wikitext parsing
1510          *
1511          * @param ParserOptions|null $options Either the ParserOption to use or null to only get the
1512          *   current ParserOption object
1513          * @return ParserOptions
1514          */
1515         public function parserOptions( $options = null ) {
1516                 if ( $options !== null && !empty( $options->isBogus ) ) {
1517                         // Someone is trying to set a bogus pre-$wgUser PO. Check if it has
1518                         // been changed somehow, and keep it if so.
1519                         $anonPO = ParserOptions::newFromAnon();
1520                         $anonPO->setEditSection( false );
1521                         if ( !$options->matches( $anonPO ) ) {
1522                                 wfLogWarning( __METHOD__ . ': Setting a changed bogus ParserOptions: ' . wfGetAllCallers( 5 ) );
1523                                 $options->isBogus = false;
1524                         }
1525                 }
1526
1527                 if ( !$this->mParserOptions ) {
1528                         if ( !$this->getContext()->getUser()->isSafeToLoad() ) {
1529                                 // $wgUser isn't unstubbable yet, so don't try to get a
1530                                 // ParserOptions for it. And don't cache this ParserOptions
1531                                 // either.
1532                                 $po = ParserOptions::newFromAnon();
1533                                 $po->setEditSection( false );
1534                                 $po->isBogus = true;
1535                                 if ( $options !== null ) {
1536                                         $this->mParserOptions = empty( $options->isBogus ) ? $options : null;
1537                                 }
1538                                 return $po;
1539                         }
1540
1541                         $this->mParserOptions = ParserOptions::newFromContext( $this->getContext() );
1542                         $this->mParserOptions->setEditSection( false );
1543                 }
1544
1545                 if ( $options !== null && !empty( $options->isBogus ) ) {
1546                         // They're trying to restore the bogus pre-$wgUser PO. Do the right
1547                         // thing.
1548                         return wfSetVar( $this->mParserOptions, null, true );
1549                 } else {
1550                         return wfSetVar( $this->mParserOptions, $options );
1551                 }
1552         }
1553
1554         /**
1555          * Set the revision ID which will be seen by the wiki text parser
1556          * for things such as embedded {{REVISIONID}} variable use.
1557          *
1558          * @param int|null $revid An positive integer, or null
1559          * @return mixed Previous value
1560          */
1561         public function setRevisionId( $revid ) {
1562                 $val = is_null( $revid ) ? null : intval( $revid );
1563                 return wfSetVar( $this->mRevisionId, $val );
1564         }
1565
1566         /**
1567          * Get the displayed revision ID
1568          *
1569          * @return int
1570          */
1571         public function getRevisionId() {
1572                 return $this->mRevisionId;
1573         }
1574
1575         /**
1576          * Set the timestamp of the revision which will be displayed. This is used
1577          * to avoid a extra DB call in Skin::lastModified().
1578          *
1579          * @param string|null $timestamp
1580          * @return mixed Previous value
1581          */
1582         public function setRevisionTimestamp( $timestamp ) {
1583                 return wfSetVar( $this->mRevisionTimestamp, $timestamp );
1584         }
1585
1586         /**
1587          * Get the timestamp of displayed revision.
1588          * This will be null if not filled by setRevisionTimestamp().
1589          *
1590          * @return string|null
1591          */
1592         public function getRevisionTimestamp() {
1593                 return $this->mRevisionTimestamp;
1594         }
1595
1596         /**
1597          * Set the displayed file version
1598          *
1599          * @param File|bool $file
1600          * @return mixed Previous value
1601          */
1602         public function setFileVersion( $file ) {
1603                 $val = null;
1604                 if ( $file instanceof File && $file->exists() ) {
1605                         $val = [ 'time' => $file->getTimestamp(), 'sha1' => $file->getSha1() ];
1606                 }
1607                 return wfSetVar( $this->mFileVersion, $val, true );
1608         }
1609
1610         /**
1611          * Get the displayed file version
1612          *
1613          * @return array|null ('time' => MW timestamp, 'sha1' => sha1)
1614          */
1615         public function getFileVersion() {
1616                 return $this->mFileVersion;
1617         }
1618
1619         /**
1620          * Get the templates used on this page
1621          *
1622          * @return array (namespace => dbKey => revId)
1623          * @since 1.18
1624          */
1625         public function getTemplateIds() {
1626                 return $this->mTemplateIds;
1627         }
1628
1629         /**
1630          * Get the files used on this page
1631          *
1632          * @return array (dbKey => array('time' => MW timestamp or null, 'sha1' => sha1 or ''))
1633          * @since 1.18
1634          */
1635         public function getFileSearchOptions() {
1636                 return $this->mImageTimeKeys;
1637         }
1638
1639         /**
1640          * Convert wikitext to HTML and add it to the buffer
1641          * Default assumes that the current page title will be used.
1642          *
1643          * @param string $text
1644          * @param bool $linestart Is this the start of a line?
1645          * @param bool $interface Is this text in the user interface language?
1646          * @throws MWException
1647          */
1648         public function addWikiText( $text, $linestart = true, $interface = true ) {
1649                 $title = $this->getTitle(); // Work around E_STRICT
1650                 if ( !$title ) {
1651                         throw new MWException( 'Title is null' );
1652                 }
1653                 $this->addWikiTextTitle( $text, $title, $linestart, /*tidy*/false, $interface );
1654         }
1655
1656         /**
1657          * Add wikitext with a custom Title object
1658          *
1659          * @param string $text Wikitext
1660          * @param Title $title
1661          * @param bool $linestart Is this the start of a line?
1662          */
1663         public function addWikiTextWithTitle( $text, &$title, $linestart = true ) {
1664                 $this->addWikiTextTitle( $text, $title, $linestart );
1665         }
1666
1667         /**
1668          * Add wikitext with a custom Title object and tidy enabled.
1669          *
1670          * @param string $text Wikitext
1671          * @param Title $title
1672          * @param bool $linestart Is this the start of a line?
1673          */
1674         function addWikiTextTitleTidy( $text, &$title, $linestart = true ) {
1675                 $this->addWikiTextTitle( $text, $title, $linestart, true );
1676         }
1677
1678         /**
1679          * Add wikitext with tidy enabled
1680          *
1681          * @param string $text Wikitext
1682          * @param bool $linestart Is this the start of a line?
1683          */
1684         public function addWikiTextTidy( $text, $linestart = true ) {
1685                 $title = $this->getTitle();
1686                 $this->addWikiTextTitleTidy( $text, $title, $linestart );
1687         }
1688
1689         /**
1690          * Add wikitext with a custom Title object
1691          *
1692          * @param string $text Wikitext
1693          * @param Title $title
1694          * @param bool $linestart Is this the start of a line?
1695          * @param bool $tidy Whether to use tidy
1696          * @param bool $interface Whether it is an interface message
1697          *   (for example disables conversion)
1698          */
1699         public function addWikiTextTitle( $text, Title $title, $linestart,
1700                 $tidy = false, $interface = false
1701         ) {
1702                 global $wgParser;
1703
1704                 $popts = $this->parserOptions();
1705                 $oldTidy = $popts->setTidy( $tidy );
1706                 $popts->setInterfaceMessage( (bool)$interface );
1707
1708                 $parserOutput = $wgParser->getFreshParser()->parse(
1709                         $text, $title, $popts,
1710                         $linestart, true, $this->mRevisionId
1711                 );
1712
1713                 $popts->setTidy( $oldTidy );
1714
1715                 $this->addParserOutput( $parserOutput );
1716
1717         }
1718
1719         /**
1720          * Add a ParserOutput object, but without Html.
1721          *
1722          * @deprecated since 1.24, use addParserOutputMetadata() instead.
1723          * @param ParserOutput $parserOutput
1724          */
1725         public function addParserOutputNoText( $parserOutput ) {
1726                 wfDeprecated( __METHOD__, '1.24' );
1727                 $this->addParserOutputMetadata( $parserOutput );
1728         }
1729
1730         /**
1731          * Add all metadata associated with a ParserOutput object, but without the actual HTML. This
1732          * includes categories, language links, ResourceLoader modules, effects of certain magic words,
1733          * and so on.
1734          *
1735          * @since 1.24
1736          * @param ParserOutput $parserOutput
1737          */
1738         public function addParserOutputMetadata( $parserOutput ) {
1739                 $this->mLanguageLinks += $parserOutput->getLanguageLinks();
1740                 $this->addCategoryLinks( $parserOutput->getCategories() );
1741                 $this->setIndicators( $parserOutput->getIndicators() );
1742                 $this->mNewSectionLink = $parserOutput->getNewSection();
1743                 $this->mHideNewSectionLink = $parserOutput->getHideNewSection();
1744
1745                 if ( !$parserOutput->isCacheable() ) {
1746                         $this->enableClientCache( false );
1747                 }
1748                 $this->mNoGallery = $parserOutput->getNoGallery();
1749                 $this->mHeadItems = array_merge( $this->mHeadItems, $parserOutput->getHeadItems() );
1750                 $this->addModules( $parserOutput->getModules() );
1751                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1752                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1753                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1754                 $this->mPreventClickjacking = $this->mPreventClickjacking
1755                         || $parserOutput->preventClickjacking();
1756
1757                 // Template versioning...
1758                 foreach ( (array)$parserOutput->getTemplateIds() as $ns => $dbks ) {
1759                         if ( isset( $this->mTemplateIds[$ns] ) ) {
1760                                 $this->mTemplateIds[$ns] = $dbks + $this->mTemplateIds[$ns];
1761                         } else {
1762                                 $this->mTemplateIds[$ns] = $dbks;
1763                         }
1764                 }
1765                 // File versioning...
1766                 foreach ( (array)$parserOutput->getFileSearchOptions() as $dbk => $data ) {
1767                         $this->mImageTimeKeys[$dbk] = $data;
1768                 }
1769
1770                 // Hooks registered in the object
1771                 $parserOutputHooks = $this->getConfig()->get( 'ParserOutputHooks' );
1772                 foreach ( $parserOutput->getOutputHooks() as $hookInfo ) {
1773                         list( $hookName, $data ) = $hookInfo;
1774                         if ( isset( $parserOutputHooks[$hookName] ) ) {
1775                                 call_user_func( $parserOutputHooks[$hookName], $this, $parserOutput, $data );
1776                         }
1777                 }
1778
1779                 // Enable OOUI if requested via ParserOutput
1780                 if ( $parserOutput->getEnableOOUI() ) {
1781                         $this->enableOOUI();
1782                 }
1783
1784                 // Include profiling data
1785                 if ( !$this->limitReportData ) {
1786                         $this->setLimitReportData( $parserOutput->getLimitReportData() );
1787                 }
1788
1789                 // Link flags are ignored for now, but may in the future be
1790                 // used to mark individual language links.
1791                 $linkFlags = [];
1792                 Hooks::run( 'LanguageLinks', [ $this->getTitle(), &$this->mLanguageLinks, &$linkFlags ] );
1793                 Hooks::run( 'OutputPageParserOutput', [ &$this, $parserOutput ] );
1794         }
1795
1796         /**
1797          * Add the HTML and enhancements for it (like ResourceLoader modules) associated with a
1798          * ParserOutput object, without any other metadata.
1799          *
1800          * @since 1.24
1801          * @param ParserOutput $parserOutput
1802          */
1803         public function addParserOutputContent( $parserOutput ) {
1804                 $this->addParserOutputText( $parserOutput );
1805
1806                 $this->addModules( $parserOutput->getModules() );
1807                 $this->addModuleScripts( $parserOutput->getModuleScripts() );
1808                 $this->addModuleStyles( $parserOutput->getModuleStyles() );
1809
1810                 $this->addJsConfigVars( $parserOutput->getJsConfigVars() );
1811         }
1812
1813         /**
1814          * Add the HTML associated with a ParserOutput object, without any metadata.
1815          *
1816          * @since 1.24
1817          * @param ParserOutput $parserOutput
1818          */
1819         public function addParserOutputText( $parserOutput ) {
1820                 $text = $parserOutput->getText();
1821                 Hooks::run( 'OutputPageBeforeHTML', [ &$this, &$text ] );
1822                 $this->addHTML( $text );
1823         }
1824
1825         /**
1826          * Add everything from a ParserOutput object.
1827          *
1828          * @param ParserOutput $parserOutput
1829          */
1830         function addParserOutput( $parserOutput ) {
1831                 $this->addParserOutputMetadata( $parserOutput );
1832                 $parserOutput->setTOCEnabled( $this->mEnableTOC );
1833
1834                 // Touch section edit links only if not previously disabled
1835                 if ( $parserOutput->getEditSectionTokens() ) {
1836                         $parserOutput->setEditSectionTokens( $this->mEnableSectionEditLinks );
1837                 }
1838
1839                 $this->addParserOutputText( $parserOutput );
1840         }
1841
1842         /**
1843          * Add the output of a QuickTemplate to the output buffer
1844          *
1845          * @param QuickTemplate $template
1846          */
1847         public function addTemplate( &$template ) {
1848                 $this->addHTML( $template->getHTML() );
1849         }
1850
1851         /**
1852          * Parse wikitext and return the HTML.
1853          *
1854          * @param string $text
1855          * @param bool $linestart Is this the start of a line?
1856          * @param bool $interface Use interface language ($wgLang instead of
1857          *   $wgContLang) while parsing language sensitive magic words like GRAMMAR and PLURAL.
1858          *   This also disables LanguageConverter.
1859          * @param Language $language Target language object, will override $interface
1860          * @throws MWException
1861          * @return string HTML
1862          */
1863         public function parse( $text, $linestart = true, $interface = false, $language = null ) {
1864                 global $wgParser;
1865
1866                 if ( is_null( $this->getTitle() ) ) {
1867                         throw new MWException( 'Empty $mTitle in ' . __METHOD__ );
1868                 }
1869
1870                 $popts = $this->parserOptions();
1871                 if ( $interface ) {
1872                         $popts->setInterfaceMessage( true );
1873                 }
1874                 if ( $language !== null ) {
1875                         $oldLang = $popts->setTargetLanguage( $language );
1876                 }
1877
1878                 $parserOutput = $wgParser->getFreshParser()->parse(
1879                         $text, $this->getTitle(), $popts,
1880                         $linestart, true, $this->mRevisionId
1881                 );
1882
1883                 if ( $interface ) {
1884                         $popts->setInterfaceMessage( false );
1885                 }
1886                 if ( $language !== null ) {
1887                         $popts->setTargetLanguage( $oldLang );
1888                 }
1889
1890                 return $parserOutput->getText();
1891         }
1892
1893         /**
1894          * Parse wikitext, strip paragraphs, and return the HTML.
1895          *
1896          * @param string $text
1897          * @param bool $linestart Is this the start of a line?
1898          * @param bool $interface Use interface language ($wgLang instead of
1899          *   $wgContLang) while parsing language sensitive magic
1900          *   words like GRAMMAR and PLURAL
1901          * @return string HTML
1902          */
1903         public function parseInline( $text, $linestart = true, $interface = false ) {
1904                 $parsed = $this->parse( $text, $linestart, $interface );
1905                 return Parser::stripOuterParagraph( $parsed );
1906         }
1907
1908         /**
1909          * @param $maxage
1910          * @deprecated since 1.27 Use setCdnMaxage() instead
1911          */
1912         public function setSquidMaxage( $maxage ) {
1913                 $this->setCdnMaxage( $maxage );
1914         }
1915
1916         /**
1917          * Set the value of the "s-maxage" part of the "Cache-control" HTTP header
1918          *
1919          * @param int $maxage Maximum cache time on the CDN, in seconds.
1920          */
1921         public function setCdnMaxage( $maxage ) {
1922                 $this->mCdnMaxage = min( $maxage, $this->mCdnMaxageLimit );
1923         }
1924
1925         /**
1926          * Lower the value of the "s-maxage" part of the "Cache-control" HTTP header
1927          *
1928          * @param int $maxage Maximum cache time on the CDN, in seconds
1929          * @since 1.27
1930          */
1931         public function lowerCdnMaxage( $maxage ) {
1932                 $this->mCdnMaxageLimit = min( $maxage, $this->mCdnMaxageLimit );
1933                 $this->setCdnMaxage( $this->mCdnMaxage );
1934         }
1935
1936         /**
1937          * Use enableClientCache(false) to force it to send nocache headers
1938          *
1939          * @param bool $state
1940          *
1941          * @return bool
1942          */
1943         public function enableClientCache( $state ) {
1944                 return wfSetVar( $this->mEnableClientCache, $state );
1945         }
1946
1947         /**
1948          * Get the list of cookies that will influence on the cache
1949          *
1950          * @return array
1951          */
1952         function getCacheVaryCookies() {
1953                 static $cookies;
1954                 if ( $cookies === null ) {
1955                         $config = $this->getConfig();
1956                         $cookies = array_merge(
1957                                 SessionManager::singleton()->getVaryCookies(),
1958                                 [
1959                                         'forceHTTPS',
1960                                 ],
1961                                 $config->get( 'CacheVaryCookies' )
1962                         );
1963                         Hooks::run( 'GetCacheVaryCookies', [ $this, &$cookies ] );
1964                 }
1965                 return $cookies;
1966         }
1967
1968         /**
1969          * Check if the request has a cache-varying cookie header
1970          * If it does, it's very important that we don't allow public caching
1971          *
1972          * @return bool
1973          */
1974         function haveCacheVaryCookies() {
1975                 $request = $this->getRequest();
1976                 foreach ( $this->getCacheVaryCookies() as $cookieName ) {
1977                         if ( $request->getCookie( $cookieName, '', '' ) !== '' ) {
1978                                 wfDebug( __METHOD__ . ": found $cookieName\n" );
1979                                 return true;
1980                         }
1981                 }
1982                 wfDebug( __METHOD__ . ": no cache-varying cookies found\n" );
1983                 return false;
1984         }
1985
1986         /**
1987          * Add an HTTP header that will influence on the cache
1988          *
1989          * @param string $header Header name
1990          * @param string[]|null $option Options for the Key header. See
1991          * https://datatracker.ietf.org/doc/draft-fielding-http-key/
1992          * for the list of valid options.
1993          */
1994         public function addVaryHeader( $header, array $option = null ) {
1995                 if ( !array_key_exists( $header, $this->mVaryHeader ) ) {
1996                         $this->mVaryHeader[$header] = [];
1997                 }
1998                 if ( !is_array( $option ) ) {
1999                         $option = [];
2000                 }
2001                 $this->mVaryHeader[$header] = array_unique( array_merge( $this->mVaryHeader[$header], $option ) );
2002         }
2003
2004         /**
2005          * Return a Vary: header on which to vary caches. Based on the keys of $mVaryHeader,
2006          * such as Accept-Encoding or Cookie
2007          *
2008          * @return string
2009          */
2010         public function getVaryHeader() {
2011                 // If we vary on cookies, let's make sure it's always included here too.
2012                 if ( $this->getCacheVaryCookies() ) {
2013                         $this->addVaryHeader( 'Cookie' );
2014                 }
2015
2016                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2017                         $this->addVaryHeader( $header, $options );
2018                 }
2019                 return 'Vary: ' . implode( ', ', array_keys( $this->mVaryHeader ) );
2020         }
2021
2022         /**
2023          * Get a complete Key header
2024          *
2025          * @return string
2026          */
2027         public function getKeyHeader() {
2028                 $cvCookies = $this->getCacheVaryCookies();
2029
2030                 $cookiesOption = [];
2031                 foreach ( $cvCookies as $cookieName ) {
2032                         $cookiesOption[] = 'param=' . $cookieName;
2033                 }
2034                 $this->addVaryHeader( 'Cookie', $cookiesOption );
2035
2036                 foreach ( SessionManager::singleton()->getVaryHeaders() as $header => $options ) {
2037                         $this->addVaryHeader( $header, $options );
2038                 }
2039
2040                 $headers = [];
2041                 foreach ( $this->mVaryHeader as $header => $option ) {
2042                         $newheader = $header;
2043                         if ( is_array( $option ) && count( $option ) > 0 ) {
2044                                 $newheader .= ';' . implode( ';', $option );
2045                         }
2046                         $headers[] = $newheader;
2047                 }
2048                 $key = 'Key: ' . implode( ',', $headers );
2049
2050                 return $key;
2051         }
2052
2053         /**
2054          * T23672: Add Accept-Language to Vary and Key headers
2055          * if there's no 'variant' parameter existed in GET.
2056          *
2057          * For example:
2058          *   /w/index.php?title=Main_page should always be served; but
2059          *   /w/index.php?title=Main_page&variant=zh-cn should never be served.
2060          */
2061         function addAcceptLanguage() {
2062                 $title = $this->getTitle();
2063                 if ( !$title instanceof Title ) {
2064                         return;
2065                 }
2066
2067                 $lang = $title->getPageLanguage();
2068                 if ( !$this->getRequest()->getCheck( 'variant' ) && $lang->hasVariants() ) {
2069                         $variants = $lang->getVariants();
2070                         $aloption = [];
2071                         foreach ( $variants as $variant ) {
2072                                 if ( $variant === $lang->getCode() ) {
2073                                         continue;
2074                                 } else {
2075                                         $aloption[] = 'substr=' . $variant;
2076
2077                                         // IE and some other browsers use BCP 47 standards in
2078                                         // their Accept-Language header, like "zh-CN" or "zh-Hant".
2079                                         // We should handle these too.
2080                                         $variantBCP47 = wfBCP47( $variant );
2081                                         if ( $variantBCP47 !== $variant ) {
2082                                                 $aloption[] = 'substr=' . $variantBCP47;
2083                                         }
2084                                 }
2085                         }
2086                         $this->addVaryHeader( 'Accept-Language', $aloption );
2087                 }
2088         }
2089
2090         /**
2091          * Set a flag which will cause an X-Frame-Options header appropriate for
2092          * edit pages to be sent. The header value is controlled by
2093          * $wgEditPageFrameOptions.
2094          *
2095          * This is the default for special pages. If you display a CSRF-protected
2096          * form on an ordinary view page, then you need to call this function.
2097          *
2098          * @param bool $enable
2099          */
2100         public function preventClickjacking( $enable = true ) {
2101                 $this->mPreventClickjacking = $enable;
2102         }
2103
2104         /**
2105          * Turn off frame-breaking. Alias for $this->preventClickjacking(false).
2106          * This can be called from pages which do not contain any CSRF-protected
2107          * HTML form.
2108          */
2109         public function allowClickjacking() {
2110                 $this->mPreventClickjacking = false;
2111         }
2112
2113         /**
2114          * Get the prevent-clickjacking flag
2115          *
2116          * @since 1.24
2117          * @return bool
2118          */
2119         public function getPreventClickjacking() {
2120                 return $this->mPreventClickjacking;
2121         }
2122
2123         /**
2124          * Get the X-Frame-Options header value (without the name part), or false
2125          * if there isn't one. This is used by Skin to determine whether to enable
2126          * JavaScript frame-breaking, for clients that don't support X-Frame-Options.
2127          *
2128          * @return string
2129          */
2130         public function getFrameOptions() {
2131                 $config = $this->getConfig();
2132                 if ( $config->get( 'BreakFrames' ) ) {
2133                         return 'DENY';
2134                 } elseif ( $this->mPreventClickjacking && $config->get( 'EditPageFrameOptions' ) ) {
2135                         return $config->get( 'EditPageFrameOptions' );
2136                 }
2137                 return false;
2138         }
2139
2140         /**
2141          * Send cache control HTTP headers
2142          */
2143         public function sendCacheControl() {
2144                 $response = $this->getRequest()->response();
2145                 $config = $this->getConfig();
2146
2147                 $this->addVaryHeader( 'Cookie' );
2148                 $this->addAcceptLanguage();
2149
2150                 # don't serve compressed data to clients who can't handle it
2151                 # maintain different caches for logged-in users and non-logged in ones
2152                 $response->header( $this->getVaryHeader() );
2153
2154                 if ( $config->get( 'UseKeyHeader' ) ) {
2155                         $response->header( $this->getKeyHeader() );
2156                 }
2157
2158                 if ( $this->mEnableClientCache ) {
2159                         if (
2160                                 $config->get( 'UseSquid' ) &&
2161                                 !$response->hasCookies() &&
2162                                 !SessionManager::getGlobalSession()->isPersistent() &&
2163                                 !$this->isPrintable() &&
2164                                 $this->mCdnMaxage != 0 &&
2165                                 !$this->haveCacheVaryCookies()
2166                         ) {
2167                                 if ( $config->get( 'UseESI' ) ) {
2168                                         # We'll purge the proxy cache explicitly, but require end user agents
2169                                         # to revalidate against the proxy on each visit.
2170                                         # Surrogate-Control controls our CDN, Cache-Control downstream caches
2171                                         wfDebug( __METHOD__ . ": proxy caching with ESI; {$this->mLastModified} **", 'private' );
2172                                         # start with a shorter timeout for initial testing
2173                                         # header( 'Surrogate-Control: max-age=2678400+2678400, content="ESI/1.0"');
2174                                         $response->header( 'Surrogate-Control: max-age=' . $config->get( 'SquidMaxage' )
2175                                                 . '+' . $this->mCdnMaxage . ', content="ESI/1.0"' );
2176                                         $response->header( 'Cache-Control: s-maxage=0, must-revalidate, max-age=0' );
2177                                 } else {
2178                                         # We'll purge the proxy cache for anons explicitly, but require end user agents
2179                                         # to revalidate against the proxy on each visit.
2180                                         # IMPORTANT! The CDN needs to replace the Cache-Control header with
2181                                         # Cache-Control: s-maxage=0, must-revalidate, max-age=0
2182                                         wfDebug( __METHOD__ . ": local proxy caching; {$this->mLastModified} **", 'private' );
2183                                         # start with a shorter timeout for initial testing
2184                                         # header( "Cache-Control: s-maxage=2678400, must-revalidate, max-age=0" );
2185                                         $response->header( 'Cache-Control: s-maxage=' . $this->mCdnMaxage
2186                                                 . ', must-revalidate, max-age=0' );
2187                                 }
2188                         } else {
2189                                 # We do want clients to cache if they can, but they *must* check for updates
2190                                 # on revisiting the page.
2191                                 wfDebug( __METHOD__ . ": private caching; {$this->mLastModified} **", 'private' );
2192                                 $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2193                                 $response->header( "Cache-Control: private, must-revalidate, max-age=0" );
2194                         }
2195                         if ( $this->mLastModified ) {
2196                                 $response->header( "Last-Modified: {$this->mLastModified}" );
2197                         }
2198                 } else {
2199                         wfDebug( __METHOD__ . ": no caching **", 'private' );
2200
2201                         # In general, the absence of a last modified header should be enough to prevent
2202                         # the client from using its cache. We send a few other things just to make sure.
2203                         $response->header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', 0 ) . ' GMT' );
2204                         $response->header( 'Cache-Control: no-cache, no-store, max-age=0, must-revalidate' );
2205                         $response->header( 'Pragma: no-cache' );
2206                 }
2207         }
2208
2209         /**
2210          * Finally, all the text has been munged and accumulated into
2211          * the object, let's actually output it:
2212          *
2213          * @param bool $return Set to true to get the result as a string rather than sending it
2214          * @return string|null
2215          * @throws Exception
2216          * @throws FatalError
2217          * @throws MWException
2218          */
2219         public function output( $return = false ) {
2220                 global $wgContLang;
2221
2222                 if ( $this->mDoNothing ) {
2223                         return $return ? '' : null;
2224                 }
2225
2226                 $response = $this->getRequest()->response();
2227                 $config = $this->getConfig();
2228
2229                 if ( $this->mRedirect != '' ) {
2230                         # Standards require redirect URLs to be absolute
2231                         $this->mRedirect = wfExpandUrl( $this->mRedirect, PROTO_CURRENT );
2232
2233                         $redirect = $this->mRedirect;
2234                         $code = $this->mRedirectCode;
2235
2236                         if ( Hooks::run( "BeforePageRedirect", [ $this, &$redirect, &$code ] ) ) {
2237                                 if ( $code == '301' || $code == '303' ) {
2238                                         if ( !$config->get( 'DebugRedirects' ) ) {
2239                                                 $response->statusHeader( $code );
2240                                         }
2241                                         $this->mLastModified = wfTimestamp( TS_RFC2822 );
2242                                 }
2243                                 if ( $config->get( 'VaryOnXFP' ) ) {
2244                                         $this->addVaryHeader( 'X-Forwarded-Proto' );
2245                                 }
2246                                 $this->sendCacheControl();
2247
2248                                 $response->header( "Content-Type: text/html; charset=utf-8" );
2249                                 if ( $config->get( 'DebugRedirects' ) ) {
2250                                         $url = htmlspecialchars( $redirect );
2251                                         print "<html>\n<head>\n<title>Redirect</title>\n</head>\n<body>\n";
2252                                         print "<p>Location: <a href=\"$url\">$url</a></p>\n";
2253                                         print "</body>\n</html>\n";
2254                                 } else {
2255                                         $response->header( 'Location: ' . $redirect );
2256                                 }
2257                         }
2258
2259                         return $return ? '' : null;
2260                 } elseif ( $this->mStatusCode ) {
2261                         $response->statusHeader( $this->mStatusCode );
2262                 }
2263
2264                 # Buffer output; final headers may depend on later processing
2265                 ob_start();
2266
2267                 $response->header( 'Content-type: ' . $config->get( 'MimeType' ) . '; charset=UTF-8' );
2268                 $response->header( 'Content-language: ' . $wgContLang->getHtmlCode() );
2269
2270                 // Avoid Internet Explorer "compatibility view" in IE 8-10, so that
2271                 // jQuery etc. can work correctly.
2272                 $response->header( 'X-UA-Compatible: IE=Edge' );
2273
2274                 // Prevent framing, if requested
2275                 $frameOptions = $this->getFrameOptions();
2276                 if ( $frameOptions ) {
2277                         $response->header( "X-Frame-Options: $frameOptions" );
2278                 }
2279
2280                 if ( $this->mArticleBodyOnly ) {
2281                         echo $this->mBodytext;
2282                 } else {
2283                         $sk = $this->getSkin();
2284                         // add skin specific modules
2285                         $modules = $sk->getDefaultModules();
2286
2287                         // Enforce various default modules for all pages and all skins
2288                         $coreModules = [
2289                                 // Keep this list as small as possible
2290                                 'site',
2291                                 'mediawiki.page.startup',
2292                                 'mediawiki.user',
2293                         ];
2294
2295                         // Support for high-density display images if enabled
2296                         if ( $config->get( 'ResponsiveImages' ) ) {
2297                                 $coreModules[] = 'mediawiki.hidpi';
2298                         }
2299
2300                         $this->addModules( $coreModules );
2301                         foreach ( $modules as $group ) {
2302                                 $this->addModules( $group );
2303                         }
2304                         MWDebug::addModules( $this );
2305
2306                         // Hook that allows last minute changes to the output page, e.g.
2307                         // adding of CSS or Javascript by extensions.
2308                         Hooks::run( 'BeforePageDisplay', [ &$this, &$sk ] );
2309
2310                         try {
2311                                 $sk->outputPage();
2312                         } catch ( Exception $e ) {
2313                                 ob_end_clean(); // bug T129657
2314                                 throw $e;
2315                         }
2316                 }
2317
2318                 try {
2319                         // This hook allows last minute changes to final overall output by modifying output buffer
2320                         Hooks::run( 'AfterFinalPageOutput', [ $this ] );
2321                 } catch ( Exception $e ) {
2322                         ob_end_clean(); // bug T129657
2323                         throw $e;
2324                 }
2325
2326                 $this->sendCacheControl();
2327
2328                 if ( $return ) {
2329                         return ob_get_clean();
2330                 } else {
2331                         ob_end_flush();
2332                         return null;
2333                 }
2334         }
2335
2336         /**
2337          * Prepare this object to display an error page; disable caching and
2338          * indexing, clear the current text and redirect, set the page's title
2339          * and optionally an custom HTML title (content of the "<title>" tag).
2340          *
2341          * @param string|Message $pageTitle Will be passed directly to setPageTitle()
2342          * @param string|Message $htmlTitle Will be passed directly to setHTMLTitle();
2343          *                   optional, if not passed the "<title>" attribute will be
2344          *                   based on $pageTitle
2345          */
2346         public function prepareErrorPage( $pageTitle, $htmlTitle = false ) {
2347                 $this->setPageTitle( $pageTitle );
2348                 if ( $htmlTitle !== false ) {
2349                         $this->setHTMLTitle( $htmlTitle );
2350                 }
2351                 $this->setRobotPolicy( 'noindex,nofollow' );
2352                 $this->setArticleRelated( false );
2353                 $this->enableClientCache( false );
2354                 $this->mRedirect = '';
2355                 $this->clearSubtitle();
2356                 $this->clearHTML();
2357         }
2358
2359         /**
2360          * Output a standard error page
2361          *
2362          * showErrorPage( 'titlemsg', 'pagetextmsg' );
2363          * showErrorPage( 'titlemsg', 'pagetextmsg', [ 'param1', 'param2' ] );
2364          * showErrorPage( 'titlemsg', $messageObject );
2365          * showErrorPage( $titleMessageObject, $messageObject );
2366          *
2367          * @param string|Message $title Message key (string) for page title, or a Message object
2368          * @param string|Message $msg Message key (string) for page text, or a Message object
2369          * @param array $params Message parameters; ignored if $msg is a Message object
2370          */
2371         public function showErrorPage( $title, $msg, $params = [] ) {
2372                 if ( !$title instanceof Message ) {
2373                         $title = $this->msg( $title );
2374                 }
2375
2376                 $this->prepareErrorPage( $title );
2377
2378                 if ( $msg instanceof Message ) {
2379                         if ( $params !== [] ) {
2380                                 trigger_error( 'Argument ignored: $params. The message parameters argument '
2381                                         . 'is discarded when the $msg argument is a Message object instead of '
2382                                         . 'a string.', E_USER_NOTICE );
2383                         }
2384                         $this->addHTML( $msg->parseAsBlock() );
2385                 } else {
2386                         $this->addWikiMsgArray( $msg, $params );
2387                 }
2388
2389                 $this->returnToMain();
2390         }
2391
2392         /**
2393          * Output a standard permission error page
2394          *
2395          * @param array $errors Error message keys or [key, param...] arrays
2396          * @param string $action Action that was denied or null if unknown
2397          */
2398         public function showPermissionsErrorPage( array $errors, $action = null ) {
2399                 foreach ( $errors as $key => $error ) {
2400                         $errors[$key] = (array)$error;
2401                 }
2402
2403                 // For some action (read, edit, create and upload), display a "login to do this action"
2404                 // error if all of the following conditions are met:
2405                 // 1. the user is not logged in
2406                 // 2. the only error is insufficient permissions (i.e. no block or something else)
2407                 // 3. the error can be avoided simply by logging in
2408                 if ( in_array( $action, [ 'read', 'edit', 'createpage', 'createtalk', 'upload' ] )
2409                         && $this->getUser()->isAnon() && count( $errors ) == 1 && isset( $errors[0][0] )
2410                         && ( $errors[0][0] == 'badaccess-groups' || $errors[0][0] == 'badaccess-group0' )
2411                         && ( User::groupHasPermission( 'user', $action )
2412                         || User::groupHasPermission( 'autoconfirmed', $action ) )
2413                 ) {
2414                         $displayReturnto = null;
2415
2416                         # Due to bug 32276, if a user does not have read permissions,
2417                         # $this->getTitle() will just give Special:Badtitle, which is
2418                         # not especially useful as a returnto parameter. Use the title
2419                         # from the request instead, if there was one.
2420                         $request = $this->getRequest();
2421                         $returnto = Title::newFromText( $request->getVal( 'title', '' ) );
2422                         if ( $action == 'edit' ) {
2423                                 $msg = 'whitelistedittext';
2424                                 $displayReturnto = $returnto;
2425                         } elseif ( $action == 'createpage' || $action == 'createtalk' ) {
2426                                 $msg = 'nocreatetext';
2427                         } elseif ( $action == 'upload' ) {
2428                                 $msg = 'uploadnologintext';
2429                         } else { # Read
2430                                 $msg = 'loginreqpagetext';
2431                                 $displayReturnto = Title::newMainPage();
2432                         }
2433
2434                         $query = [];
2435
2436                         if ( $returnto ) {
2437                                 $query['returnto'] = $returnto->getPrefixedText();
2438
2439                                 if ( !$request->wasPosted() ) {
2440                                         $returntoquery = $request->getValues();
2441                                         unset( $returntoquery['title'] );
2442                                         unset( $returntoquery['returnto'] );
2443                                         unset( $returntoquery['returntoquery'] );
2444                                         $query['returntoquery'] = wfArrayToCgi( $returntoquery );
2445                                 }
2446                         }
2447                         $loginLink = Linker::linkKnown(
2448                                 SpecialPage::getTitleFor( 'Userlogin' ),
2449                                 $this->msg( 'loginreqlink' )->escaped(),
2450                                 [],
2451                                 $query
2452                         );
2453
2454                         $this->prepareErrorPage( $this->msg( 'loginreqtitle' ) );
2455                         $this->addHTML( $this->msg( $msg )->rawParams( $loginLink )->parse() );
2456
2457                         # Don't return to a page the user can't read otherwise
2458                         # we'll end up in a pointless loop
2459                         if ( $displayReturnto && $displayReturnto->userCan( 'read', $this->getUser() ) ) {
2460                                 $this->returnToMain( null, $displayReturnto );
2461                         }
2462                 } else {
2463                         $this->prepareErrorPage( $this->msg( 'permissionserrors' ) );
2464                         $this->addWikiText( $this->formatPermissionsErrorMessage( $errors, $action ) );
2465                 }
2466         }
2467
2468         /**
2469          * Display an error page indicating that a given version of MediaWiki is
2470          * required to use it
2471          *
2472          * @param mixed $version The version of MediaWiki needed to use the page
2473          */
2474         public function versionRequired( $version ) {
2475                 $this->prepareErrorPage( $this->msg( 'versionrequired', $version ) );
2476
2477                 $this->addWikiMsg( 'versionrequiredtext', $version );
2478                 $this->returnToMain();
2479         }
2480
2481         /**
2482          * Format a list of error messages
2483          *
2484          * @param array $errors Array of arrays returned by Title::getUserPermissionsErrors
2485          * @param string $action Action that was denied or null if unknown
2486          * @return string The wikitext error-messages, formatted into a list.
2487          */
2488         public function formatPermissionsErrorMessage( array $errors, $action = null ) {
2489                 if ( $action == null ) {
2490                         $text = $this->msg( 'permissionserrorstext', count( $errors ) )->plain() . "\n\n";
2491                 } else {
2492                         $action_desc = $this->msg( "action-$action" )->plain();
2493                         $text = $this->msg(
2494                                 'permissionserrorstext-withaction',
2495                                 count( $errors ),
2496                                 $action_desc
2497                         )->plain() . "\n\n";
2498                 }
2499
2500                 if ( count( $errors ) > 1 ) {
2501                         $text .= '<ul class="permissions-errors">' . "\n";
2502
2503                         foreach ( $errors as $error ) {
2504                                 $text .= '<li>';
2505                                 $text .= call_user_func_array( [ $this, 'msg' ], $error )->plain();
2506                                 $text .= "</li>\n";
2507                         }
2508                         $text .= '</ul>';
2509                 } else {
2510                         $text .= "<div class=\"permissions-errors\">\n" .
2511                                         call_user_func_array( [ $this, 'msg' ], reset( $errors ) )->plain() .
2512                                         "\n</div>";
2513                 }
2514
2515                 return $text;
2516         }
2517
2518         /**
2519          * Display a page stating that the Wiki is in read-only mode.
2520          * Should only be called after wfReadOnly() has returned true.
2521          *
2522          * Historically, this function was used to show the source of the page that the user
2523          * was trying to edit and _also_ permissions error messages. The relevant code was
2524          * moved into EditPage in 1.19 (r102024 / d83c2a431c2a) and removed here in 1.25.
2525          *
2526          * @deprecated since 1.25; throw the exception directly
2527          * @throws ReadOnlyError
2528          */
2529         public function readOnlyPage() {
2530                 if ( func_num_args() > 0 ) {
2531                         throw new MWException( __METHOD__ . ' no longer accepts arguments since 1.25.' );
2532                 }
2533
2534                 throw new ReadOnlyError;
2535         }
2536
2537         /**
2538          * Turn off regular page output and return an error response
2539          * for when rate limiting has triggered.
2540          *
2541          * @deprecated since 1.25; throw the exception directly
2542          */
2543         public function rateLimited() {
2544                 wfDeprecated( __METHOD__, '1.25' );
2545                 throw new ThrottledError;
2546         }
2547
2548         /**
2549          * Show a warning about replica DB lag
2550          *
2551          * If the lag is higher than $wgSlaveLagCritical seconds,
2552          * then the warning is a bit more obvious. If the lag is
2553          * lower than $wgSlaveLagWarning, then no warning is shown.
2554          *
2555          * @param int $lag Slave lag
2556          */
2557         public function showLagWarning( $lag ) {
2558                 $config = $this->getConfig();
2559                 if ( $lag >= $config->get( 'SlaveLagWarning' ) ) {
2560                         $lag = floor( $lag ); // floor to avoid nano seconds to display
2561                         $message = $lag < $config->get( 'SlaveLagCritical' )
2562                                 ? 'lag-warn-normal'
2563                                 : 'lag-warn-high';
2564                         $wrap = Html::rawElement( 'div', [ 'class' => "mw-{$message}" ], "\n$1\n" );
2565                         $this->wrapWikiMsg( "$wrap\n", [ $message, $this->getLanguage()->formatNum( $lag ) ] );
2566                 }
2567         }
2568
2569         public function showFatalError( $message ) {
2570                 $this->prepareErrorPage( $this->msg( 'internalerror' ) );
2571
2572                 $this->addHTML( $message );
2573         }
2574
2575         public function showUnexpectedValueError( $name, $val ) {
2576                 $this->showFatalError( $this->msg( 'unexpected', $name, $val )->text() );
2577         }
2578
2579         public function showFileCopyError( $old, $new ) {
2580                 $this->showFatalError( $this->msg( 'filecopyerror', $old, $new )->text() );
2581         }
2582
2583         public function showFileRenameError( $old, $new ) {
2584                 $this->showFatalError( $this->msg( 'filerenameerror', $old, $new )->text() );
2585         }
2586
2587         public function showFileDeleteError( $name ) {
2588                 $this->showFatalError( $this->msg( 'filedeleteerror', $name )->text() );
2589         }
2590
2591         public function showFileNotFoundError( $name ) {
2592                 $this->showFatalError( $this->msg( 'filenotfound', $name )->text() );
2593         }
2594
2595         /**
2596          * Add a "return to" link pointing to a specified title
2597          *
2598          * @param Title $title Title to link
2599          * @param array $query Query string parameters
2600          * @param string $text Text of the link (input is not escaped)
2601          * @param array $options Options array to pass to Linker
2602          */
2603         public function addReturnTo( $title, array $query = [], $text = null, $options = [] ) {
2604                 $link = $this->msg( 'returnto' )->rawParams(
2605                         Linker::link( $title, $text, [], $query, $options ) )->escaped();
2606                 $this->addHTML( "<p id=\"mw-returnto\">{$link}</p>\n" );
2607         }
2608
2609         /**
2610          * Add a "return to" link pointing to a specified title,
2611          * or the title indicated in the request, or else the main page
2612          *
2613          * @param mixed $unused
2614          * @param Title|string $returnto Title or String to return to
2615          * @param string $returntoquery Query string for the return to link
2616          */
2617         public function returnToMain( $unused = null, $returnto = null, $returntoquery = null ) {
2618                 if ( $returnto == null ) {
2619                         $returnto = $this->getRequest()->getText( 'returnto' );
2620                 }
2621
2622                 if ( $returntoquery == null ) {
2623                         $returntoquery = $this->getRequest()->getText( 'returntoquery' );
2624                 }
2625
2626                 if ( $returnto === '' ) {
2627                         $returnto = Title::newMainPage();
2628                 }
2629
2630                 if ( is_object( $returnto ) ) {
2631                         $titleObj = $returnto;
2632                 } else {
2633                         $titleObj = Title::newFromText( $returnto );
2634                 }
2635                 if ( !is_object( $titleObj ) ) {
2636                         $titleObj = Title::newMainPage();
2637                 }
2638
2639                 $this->addReturnTo( $titleObj, wfCgiToArray( $returntoquery ) );
2640         }
2641
2642         private function getRlClientContext() {
2643                 if ( !$this->rlClientContext ) {
2644                         $query = ResourceLoader::makeLoaderQuery(
2645                                 [], // modules; not relevant
2646                                 $this->getLanguage()->getCode(),
2647                                 $this->getSkin()->getSkinName(),
2648                                 $this->getUser()->isLoggedIn() ? $this->getUser()->getName() : null,
2649                                 null, // version; not relevant
2650                                 ResourceLoader::inDebugMode(),
2651                                 null, // only; not relevant
2652                                 $this->isPrintable(),
2653                                 $this->getRequest()->getBool( 'handheld' )
2654                         );
2655                         $this->rlClientContext = new ResourceLoaderContext(
2656                                 $this->getResourceLoader(),
2657                                 new FauxRequest( $query )
2658                         );
2659                 }
2660                 return $this->rlClientContext;
2661         }
2662
2663         /**
2664          * Call this to freeze the module queue and JS config and create a formatter.
2665          *
2666          * Depending on the Skin, this may get lazy-initialised in either headElement() or
2667          * getBottomScripts(). See SkinTemplate::prepareQuickTemplate(). Calling this too early may
2668          * cause unexpected side-effects since disallowUserJs() may be called at any time to change
2669          * the module filters retroactively. Skins and extension hooks may also add modules until very
2670          * late in the request lifecycle.
2671          *
2672          * @return ResourceLoaderClientHtml
2673          */
2674         public function getRlClient() {
2675                 if ( !$this->rlClient ) {
2676                         $context = $this->getRlClientContext();
2677                         $rl = $this->getResourceLoader();
2678                         $this->addModules( [
2679                                 'user.options',
2680                                 'user.tokens',
2681                         ] );
2682                         $this->addModuleStyles( [
2683                                 'site.styles',
2684                                 'noscript',
2685                                 'user.styles',
2686                                 'user.cssprefs',
2687                         ] );
2688                         $this->getSkin()->setupSkinUserCss( $this );
2689
2690                         // Prepare exempt modules for buildExemptModules()
2691                         $exemptGroups = [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ];
2692                         $exemptStates = [];
2693                         $moduleStyles = $this->getModuleStyles( /*filter*/ true );
2694
2695                         // Preload getTitleInfo for isKnownEmpty calls below and in ResourceLoaderClientHtml
2696                         // Separate user-specific batch for improved cache-hit ratio.
2697                         $userBatch = [ 'user.styles', 'user' ];
2698                         $siteBatch = array_diff( $moduleStyles, $userBatch );
2699                         $dbr = wfGetDB( DB_REPLICA );
2700                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $siteBatch );
2701                         ResourceLoaderWikiModule::preloadTitleInfo( $context, $dbr, $userBatch );
2702
2703                         // Filter out modules handled by buildExemptModules()
2704                         $moduleStyles = array_filter( $moduleStyles,
2705                                 function ( $name ) use ( $rl, $context, &$exemptGroups, &$exemptStates ) {
2706                                         $module = $rl->getModule( $name );
2707                                         if ( $module ) {
2708                                                 if ( $name === 'user.styles' && $this->isUserCssPreview() ) {
2709                                                         $exemptStates[$name] = 'ready';
2710                                                         // Special case in buildExemptModules()
2711                                                         return false;
2712                                                 }
2713                                                 $group = $module->getGroup();
2714                                                 if ( isset( $exemptGroups[$group] ) ) {
2715                                                         $exemptStates[$name] = 'ready';
2716                                                         if ( !$module->isKnownEmpty( $context ) ) {
2717                                                                 // E.g. Don't output empty <styles>
2718                                                                 $exemptGroups[$group][] = $name;
2719                                                         }
2720                                                         return false;
2721                                                 }
2722                                         }
2723                                         return true;
2724                                 }
2725                         );
2726                         $this->rlExemptStyleModules = $exemptGroups;
2727
2728                         $isUserModuleFiltered = !$this->filterModules( [ 'user' ] );
2729                         // If this page filters out 'user', makeResourceLoaderLink will drop it.
2730                         // Avoid indefinite "loading" state or untrue "ready" state (T145368).
2731                         if ( !$isUserModuleFiltered ) {
2732                                 // Manually handled by getBottomScripts()
2733                                 $userModule = $rl->getModule( 'user' );
2734                                 $userState = $userModule->isKnownEmpty( $context ) && !$this->isUserJsPreview()
2735                                         ? 'ready'
2736                                         : 'loading';
2737                                 $this->rlUserModuleState = $exemptStates['user'] = $userState;
2738                         }
2739
2740                         $rlClient = new ResourceLoaderClientHtml( $context, $this->getTarget() );
2741                         $rlClient->setConfig( $this->getJSVars() );
2742                         $rlClient->setModules( $this->getModules( /*filter*/ true ) );
2743                         $rlClient->setModuleStyles( $moduleStyles );
2744                         $rlClient->setModuleScripts( $this->getModuleScripts( /*filter*/ true ) );
2745                         $rlClient->setExemptStates( $exemptStates );
2746                         $this->rlClient = $rlClient;
2747                 }
2748                 return $this->rlClient;
2749         }
2750
2751         /**
2752          * @param Skin $sk The given Skin
2753          * @param bool $includeStyle Unused
2754          * @return string The doctype, opening "<html>", and head element.
2755          */
2756         public function headElement( Skin $sk, $includeStyle = true ) {
2757                 global $wgContLang;
2758
2759                 $userdir = $this->getLanguage()->getDir();
2760                 $sitedir = $wgContLang->getDir();
2761
2762                 $pieces = [];
2763                 $pieces[] = Html::htmlHeader( Sanitizer::mergeAttributes(
2764                         $this->getRlClient()->getDocumentAttributes(),
2765                         $sk->getHtmlElementAttributes()
2766                 ) );
2767                 $pieces[] = Html::openElement( 'head' );
2768
2769                 if ( $this->getHTMLTitle() == '' ) {
2770                         $this->setHTMLTitle( $this->msg( 'pagetitle', $this->getPageTitle() )->inContentLanguage() );
2771                 }
2772
2773                 if ( !Html::isXmlMimeType( $this->getConfig()->get( 'MimeType' ) ) ) {
2774                         // Add <meta charset="UTF-8">
2775                         // This should be before <title> since it defines the charset used by
2776                         // text including the text inside <title>.
2777                         // The spec recommends defining XHTML5's charset using the XML declaration
2778                         // instead of meta.
2779                         // Our XML declaration is output by Html::htmlHeader.
2780                         // http://www.whatwg.org/html/semantics.html#attr-meta-http-equiv-content-type
2781                         // http://www.whatwg.org/html/semantics.html#charset
2782                         $pieces[] = Html::element( 'meta', [ 'charset' => 'UTF-8' ] );
2783                 }
2784
2785                 $pieces[] = Html::element( 'title', null, $this->getHTMLTitle() );
2786                 $pieces[] = $this->getRlClient()->getHeadHtml();
2787                 $pieces[] = $this->buildExemptModules();
2788                 $pieces = array_merge( $pieces, array_values( $this->getHeadLinksArray() ) );
2789                 $pieces = array_merge( $pieces, array_values( $this->mHeadItems ) );
2790                 $pieces[] = Html::closeElement( 'head' );
2791
2792                 $bodyClasses = [];
2793                 $bodyClasses[] = 'mediawiki';
2794
2795                 # Classes for LTR/RTL directionality support
2796                 $bodyClasses[] = $userdir;
2797                 $bodyClasses[] = "sitedir-$sitedir";
2798
2799                 if ( $this->getLanguage()->capitalizeAllNouns() ) {
2800                         # A <body> class is probably not the best way to do this . . .
2801                         $bodyClasses[] = 'capitalize-all-nouns';
2802                 }
2803
2804                 // Parser feature migration class
2805                 // The idea is that this will eventually be removed, after the wikitext
2806                 // which requires it is cleaned up.
2807                 $bodyClasses[] = 'mw-hide-empty-elt';
2808
2809                 $bodyClasses[] = $sk->getPageClasses( $this->getTitle() );
2810                 $bodyClasses[] = 'skin-' . Sanitizer::escapeClass( $sk->getSkinName() );
2811                 $bodyClasses[] =
2812                         'action-' . Sanitizer::escapeClass( Action::getActionName( $this->getContext() ) );
2813
2814                 $bodyAttrs = [];
2815                 // While the implode() is not strictly needed, it's used for backwards compatibility
2816                 // (this used to be built as a string and hooks likely still expect that).
2817                 $bodyAttrs['class'] = implode( ' ', $bodyClasses );
2818
2819                 // Allow skins and extensions to add body attributes they need
2820                 $sk->addToBodyAttributes( $this, $bodyAttrs );
2821                 Hooks::run( 'OutputPageBodyAttributes', [ $this, $sk, &$bodyAttrs ] );
2822
2823                 $pieces[] = Html::openElement( 'body', $bodyAttrs );
2824
2825                 return self::combineWrappedStrings( $pieces );
2826         }
2827
2828         /**
2829          * Get a ResourceLoader object associated with this OutputPage
2830          *
2831          * @return ResourceLoader
2832          */
2833         public function getResourceLoader() {
2834                 if ( is_null( $this->mResourceLoader ) ) {
2835                         $this->mResourceLoader = new ResourceLoader(
2836                                 $this->getConfig(),
2837                                 LoggerFactory::getInstance( 'resourceloader' )
2838                         );
2839                 }
2840                 return $this->mResourceLoader;
2841         }
2842
2843         /**
2844          * Explicily load or embed modules on a page.
2845          *
2846          * @param array|string $modules One or more module names
2847          * @param string $only ResourceLoaderModule TYPE_ class constant
2848          * @param array $extraQuery [optional] Array with extra query parameters for the request
2849          * @return string|WrappedStringList HTML
2850          */
2851         public function makeResourceLoaderLink( $modules, $only, array $extraQuery = [] ) {
2852                 // Apply 'target' and 'origin' filters
2853                 $modules = $this->filterModules( (array)$modules, null, $only );
2854
2855                 return ResourceLoaderClientHtml::makeLoad(
2856                         $this->getRlClientContext(),
2857                         $modules,
2858                         $only,
2859                         $extraQuery
2860                 );
2861         }
2862
2863         /**
2864          * Combine WrappedString chunks and filter out empty ones
2865          *
2866          * @param array $chunks
2867          * @return string|WrappedStringList HTML
2868          */
2869         protected static function combineWrappedStrings( array $chunks ) {
2870                 // Filter out empty values
2871                 $chunks = array_filter( $chunks, 'strlen' );
2872                 return WrappedString::join( "\n", $chunks );
2873         }
2874
2875         private function isUserJsPreview() {
2876                 return $this->getConfig()->get( 'AllowUserJs' )
2877                         && $this->getTitle()
2878                         && $this->getTitle()->isJsSubpage()
2879                         && $this->userCanPreview();
2880         }
2881
2882         private function isUserCssPreview() {
2883                 return $this->getConfig()->get( 'AllowUserCss' )
2884                         && $this->getTitle()
2885                         && $this->getTitle()->isCssSubpage()
2886                         && $this->userCanPreview();
2887         }
2888
2889         /**
2890          * JS stuff to put at the bottom of the `<body>`. These are modules with position 'bottom',
2891          * legacy scripts ($this->mScripts), and user JS.
2892          *
2893          * @return string|WrappedStringList HTML
2894          */
2895         public function getBottomScripts() {
2896                 $chunks = [];
2897                 $chunks[] = $this->getRlClient()->getBodyHtml();
2898
2899                 // Legacy non-ResourceLoader scripts
2900                 $chunks[] = $this->mScripts;
2901
2902                 // Exempt 'user' module
2903                 // - May need excludepages for live preview. (T28283)
2904                 // - Must use TYPE_COMBINED so its response is handled by mw.loader.implement() which
2905                 //   ensures execution is scheduled after the "site" module.
2906                 // - Don't load if module state is already resolved as "ready".
2907                 if ( $this->rlUserModuleState === 'loading' ) {
2908                         if ( $this->isUserJsPreview() ) {
2909                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED,
2910                                         [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
2911                                 );
2912                                 $chunks[] = ResourceLoader::makeInlineScript(
2913                                         Xml::encodeJsCall( 'mw.loader.using', [
2914                                                 [ 'user', 'site' ],
2915                                                 new XmlJsCode(
2916                                                         'function () {'
2917                                                                 . Xml::encodeJsCall( '$.globalEval', [
2918                                                                         $this->getRequest()->getText( 'wpTextbox1' )
2919                                                                 ] )
2920                                                                 . '}'
2921                                                 )
2922                                         ] )
2923                                 );
2924                                 // FIXME: If the user is previewing, say, ./vector.js, his ./common.js will be loaded
2925                                 // asynchronously and may arrive *after* the inline script here. So the previewed code
2926                                 // may execute before ./common.js runs. Normally, ./common.js runs before ./vector.js.
2927                                 // Similarly, when previewing ./common.js and the user module does arrive first,
2928                                 // it will arrive without common.js and the inline script runs after.
2929                                 // Thus running common after the excluded subpage.
2930                         } else {
2931                                 // Load normally
2932                                 $chunks[] = $this->makeResourceLoaderLink( 'user', ResourceLoaderModule::TYPE_COMBINED );
2933                         }
2934                 }
2935
2936                 if ( $this->limitReportData ) {
2937                         $chunks[] = ResourceLoader::makeInlineScript(
2938                                 ResourceLoader::makeConfigSetScript(
2939                                         [ 'wgPageParseReport' => $this->limitReportData ],
2940                                         true
2941                                 )
2942                         );
2943                 }
2944
2945                 return self::combineWrappedStrings( $chunks );
2946         }
2947
2948         /**
2949          * Get the javascript config vars to include on this page
2950          *
2951          * @return array Array of javascript config vars
2952          * @since 1.23
2953          */
2954         public function getJsConfigVars() {
2955                 return $this->mJsConfigVars;
2956         }
2957
2958         /**
2959          * Add one or more variables to be set in mw.config in JavaScript
2960          *
2961          * @param string|array $keys Key or array of key/value pairs
2962          * @param mixed $value [optional] Value of the configuration variable
2963          */
2964         public function addJsConfigVars( $keys, $value = null ) {
2965                 if ( is_array( $keys ) ) {
2966                         foreach ( $keys as $key => $value ) {
2967                                 $this->mJsConfigVars[$key] = $value;
2968                         }
2969                         return;
2970                 }
2971
2972                 $this->mJsConfigVars[$keys] = $value;
2973         }
2974
2975         /**
2976          * Get an array containing the variables to be set in mw.config in JavaScript.
2977          *
2978          * Do not add things here which can be evaluated in ResourceLoaderStartUpModule
2979          * - in other words, page-independent/site-wide variables (without state).
2980          * You will only be adding bloat to the html page and causing page caches to
2981          * have to be purged on configuration changes.
2982          * @return array
2983          */
2984         public function getJSVars() {
2985                 global $wgContLang;
2986
2987                 $curRevisionId = 0;
2988                 $articleId = 0;
2989                 $canonicalSpecialPageName = false; # bug 21115
2990
2991                 $title = $this->getTitle();
2992                 $ns = $title->getNamespace();
2993                 $canonicalNamespace = MWNamespace::exists( $ns )
2994                         ? MWNamespace::getCanonicalName( $ns )
2995                         : $title->getNsText();
2996
2997                 $sk = $this->getSkin();
2998                 // Get the relevant title so that AJAX features can use the correct page name
2999                 // when making API requests from certain special pages (bug 34972).
3000                 $relevantTitle = $sk->getRelevantTitle();
3001                 $relevantUser = $sk->getRelevantUser();
3002
3003                 if ( $ns == NS_SPECIAL ) {
3004                         list( $canonicalSpecialPageName, /*...*/ ) =
3005                                 SpecialPageFactory::resolveAlias( $title->getDBkey() );
3006                 } elseif ( $this->canUseWikiPage() ) {
3007                         $wikiPage = $this->getWikiPage();
3008                         $curRevisionId = $wikiPage->getLatest();
3009                         $articleId = $wikiPage->getId();
3010                 }
3011
3012                 $lang = $title->getPageViewLanguage();
3013
3014                 // Pre-process information
3015                 $separatorTransTable = $lang->separatorTransformTable();
3016                 $separatorTransTable = $separatorTransTable ? $separatorTransTable : [];
3017                 $compactSeparatorTransTable = [
3018                         implode( "\t", array_keys( $separatorTransTable ) ),
3019                         implode( "\t", $separatorTransTable ),
3020                 ];
3021                 $digitTransTable = $lang->digitTransformTable();
3022                 $digitTransTable = $digitTransTable ? $digitTransTable : [];
3023                 $compactDigitTransTable = [
3024                         implode( "\t", array_keys( $digitTransTable ) ),
3025                         implode( "\t", $digitTransTable ),
3026                 ];
3027
3028                 $user = $this->getUser();
3029
3030                 $vars = [
3031                         'wgCanonicalNamespace' => $canonicalNamespace,
3032                         'wgCanonicalSpecialPageName' => $canonicalSpecialPageName,
3033                         'wgNamespaceNumber' => $title->getNamespace(),
3034                         'wgPageName' => $title->getPrefixedDBkey(),
3035                         'wgTitle' => $title->getText(),
3036                         'wgCurRevisionId' => $curRevisionId,
3037                         'wgRevisionId' => (int)$this->getRevisionId(),
3038                         'wgArticleId' => $articleId,
3039                         'wgIsArticle' => $this->isArticle(),
3040                         'wgIsRedirect' => $title->isRedirect(),
3041                         'wgAction' => Action::getActionName( $this->getContext() ),
3042                         'wgUserName' => $user->isAnon() ? null : $user->getName(),
3043                         'wgUserGroups' => $user->getEffectiveGroups(),
3044                         'wgCategories' => $this->getCategories(),
3045                         'wgBreakFrames' => $this->getFrameOptions() == 'DENY',
3046                         'wgPageContentLanguage' => $lang->getCode(),
3047                         'wgPageContentModel' => $title->getContentModel(),
3048                         'wgSeparatorTransformTable' => $compactSeparatorTransTable,
3049                         'wgDigitTransformTable' => $compactDigitTransTable,
3050                         'wgDefaultDateFormat' => $lang->getDefaultDateFormat(),
3051                         'wgMonthNames' => $lang->getMonthNamesArray(),
3052                         'wgMonthNamesShort' => $lang->getMonthAbbreviationsArray(),
3053                         'wgRelevantPageName' => $relevantTitle->getPrefixedDBkey(),
3054                         'wgRelevantArticleId' => $relevantTitle->getArticleID(),
3055                         'wgRequestId' => WebRequest::getRequestId(),
3056                 ];
3057
3058                 if ( $user->isLoggedIn() ) {
3059                         $vars['wgUserId'] = $user->getId();
3060                         $vars['wgUserEditCount'] = $user->getEditCount();
3061                         $userReg = $user->getRegistration();
3062                         $vars['wgUserRegistration'] = $userReg ? wfTimestamp( TS_UNIX, $userReg ) * 1000 : null;
3063                         // Get the revision ID of the oldest new message on the user's talk
3064                         // page. This can be used for constructing new message alerts on
3065                         // the client side.
3066                         $vars['wgUserNewMsgRevisionId'] = $user->getNewMessageRevisionId();
3067                 }
3068
3069                 if ( $wgContLang->hasVariants() ) {
3070                         $vars['wgUserVariant'] = $wgContLang->getPreferredVariant();
3071                 }
3072                 // Same test as SkinTemplate
3073                 $vars['wgIsProbablyEditable'] = $title->quickUserCan( 'edit', $user )
3074                         && ( $title->exists() || $title->quickUserCan( 'create', $user ) );
3075
3076                 foreach ( $title->getRestrictionTypes() as $type ) {
3077                         $vars['wgRestriction' . ucfirst( $type )] = $title->getRestrictions( $type );
3078                 }
3079
3080                 if ( $title->isMainPage() ) {
3081                         $vars['wgIsMainPage'] = true;
3082                 }
3083
3084                 if ( $this->mRedirectedFrom ) {
3085                         $vars['wgRedirectedFrom'] = $this->mRedirectedFrom->getPrefixedDBkey();
3086                 }
3087
3088                 if ( $relevantUser ) {
3089                         $vars['wgRelevantUserName'] = $relevantUser->getName();
3090                 }
3091
3092                 // Allow extensions to add their custom variables to the mw.config map.
3093                 // Use the 'ResourceLoaderGetConfigVars' hook if the variable is not
3094                 // page-dependant but site-wide (without state).
3095                 // Alternatively, you may want to use OutputPage->addJsConfigVars() instead.
3096                 Hooks::run( 'MakeGlobalVariablesScript', [ &$vars, $this ] );
3097
3098                 // Merge in variables from addJsConfigVars last
3099                 return array_merge( $vars, $this->getJsConfigVars() );
3100         }
3101
3102         /**
3103          * To make it harder for someone to slip a user a fake
3104          * user-JavaScript or user-CSS preview, a random token
3105          * is associated with the login session. If it's not
3106          * passed back with the preview request, we won't render
3107          * the code.
3108          *
3109          * @return bool
3110          */
3111         public function userCanPreview() {
3112                 $request = $this->getRequest();
3113                 if (
3114                         $request->getVal( 'action' ) !== 'submit' ||
3115                         !$request->getCheck( 'wpPreview' ) ||
3116                         !$request->wasPosted()
3117                 ) {
3118                         return false;
3119                 }
3120
3121                 $user = $this->getUser();
3122
3123                 if ( !$user->isLoggedIn() ) {
3124                         // Anons have predictable edit tokens
3125                         return false;
3126                 }
3127                 if ( !$user->matchEditToken( $request->getVal( 'wpEditToken' ) ) ) {
3128                         return false;
3129                 }
3130
3131                 $title = $this->getTitle();
3132                 if ( !$title->isJsSubpage() && !$title->isCssSubpage() ) {
3133                         return false;
3134                 }
3135                 if ( !$title->isSubpageOf( $user->getUserPage() ) ) {
3136                         // Don't execute another user's CSS or JS on preview (T85855)
3137                         return false;
3138                 }
3139
3140                 $errors = $title->getUserPermissionsErrors( 'edit', $user );
3141                 if ( count( $errors ) !== 0 ) {
3142                         return false;
3143                 }
3144
3145                 return true;
3146         }
3147
3148         /**
3149          * @return array Array in format "link name or number => 'link html'".
3150          */
3151         public function getHeadLinksArray() {
3152                 global $wgVersion;
3153
3154                 $tags = [];
3155                 $config = $this->getConfig();
3156
3157                 $canonicalUrl = $this->mCanonicalUrl;
3158
3159                 $tags['meta-generator'] = Html::element( 'meta', [
3160                         'name' => 'generator',
3161                         'content' => "MediaWiki $wgVersion",
3162                 ] );
3163
3164                 if ( $config->get( 'ReferrerPolicy' ) !== false ) {
3165                         $tags['meta-referrer'] = Html::element( 'meta', [
3166                                 'name' => 'referrer',
3167                                 'content' => $config->get( 'ReferrerPolicy' )
3168                         ] );
3169                 }
3170
3171                 $p = "{$this->mIndexPolicy},{$this->mFollowPolicy}";
3172                 if ( $p !== 'index,follow' ) {
3173                         // http://www.robotstxt.org/wc/meta-user.html
3174                         // Only show if it's different from the default robots policy
3175                         $tags['meta-robots'] = Html::element( 'meta', [
3176                                 'name' => 'robots',
3177                                 'content' => $p,
3178                         ] );
3179                 }
3180
3181                 foreach ( $this->mMetatags as $tag ) {
3182                         if ( 0 == strcasecmp( 'http:', substr( $tag[0], 0, 5 ) ) ) {
3183                                 $a = 'http-equiv';
3184                                 $tag[0] = substr( $tag[0], 5 );
3185                         } else {
3186                                 $a = 'name';
3187                         }
3188                         $tagName = "meta-{$tag[0]}";
3189                         if ( isset( $tags[$tagName] ) ) {
3190                                 $tagName .= $tag[1];
3191                         }
3192                         $tags[$tagName] = Html::element( 'meta',
3193                                 [
3194                                         $a => $tag[0],
3195                                         'content' => $tag[1]
3196                                 ]
3197                         );
3198                 }
3199
3200                 foreach ( $this->mLinktags as $tag ) {
3201                         $tags[] = Html::element( 'link', $tag );
3202                 }
3203
3204                 # Universal edit button
3205                 if ( $config->get( 'UniversalEditButton' ) && $this->isArticleRelated() ) {
3206                         $user = $this->getUser();
3207                         if ( $this->getTitle()->quickUserCan( 'edit', $user )
3208                                 && ( $this->getTitle()->exists() ||
3209                                         $this->getTitle()->quickUserCan( 'create', $user ) )
3210                         ) {
3211                                 // Original UniversalEditButton
3212                                 $msg = $this->msg( 'edit' )->text();
3213                                 $tags['universal-edit-button'] = Html::element( 'link', [
3214                                         'rel' => 'alternate',
3215                                         'type' => 'application/x-wiki',
3216                                         'title' => $msg,
3217                                         'href' => $this->getTitle()->getEditURL(),
3218                                 ] );
3219                                 // Alternate edit link
3220                                 $tags['alternative-edit'] = Html::element( 'link', [
3221                                         'rel' => 'edit',
3222                                         'title' => $msg,
3223                                         'href' => $this->getTitle()->getEditURL(),
3224                                 ] );
3225                         }
3226                 }
3227
3228                 # Generally the order of the favicon and apple-touch-icon links
3229                 # should not matter, but Konqueror (3.5.9 at least) incorrectly
3230                 # uses whichever one appears later in the HTML source. Make sure
3231                 # apple-touch-icon is specified first to avoid this.
3232                 if ( $config->get( 'AppleTouchIcon' ) !== false ) {
3233                         $tags['apple-touch-icon'] = Html::element( 'link', [
3234                                 'rel' => 'apple-touch-icon',
3235                                 'href' => $config->get( 'AppleTouchIcon' )
3236                         ] );
3237                 }
3238
3239                 if ( $config->get( 'Favicon' ) !== false ) {
3240                         $tags['favicon'] = Html::element( 'link', [
3241                                 'rel' => 'shortcut icon',
3242                                 'href' => $config->get( 'Favicon' )
3243                         ] );
3244                 }
3245
3246                 # OpenSearch description link
3247                 $tags['opensearch'] = Html::element( 'link', [
3248                         'rel' => 'search',
3249                         'type' => 'application/opensearchdescription+xml',
3250                         'href' => wfScript( 'opensearch_desc' ),
3251                         'title' => $this->msg( 'opensearch-desc' )->inContentLanguage()->text(),
3252                 ] );
3253
3254                 if ( $config->get( 'EnableAPI' ) ) {
3255                         # Real Simple Discovery link, provides auto-discovery information
3256                         # for the MediaWiki API (and potentially additional custom API
3257                         # support such as WordPress or Twitter-compatible APIs for a
3258                         # blogging extension, etc)
3259                         $tags['rsd'] = Html::element( 'link', [
3260                                 'rel' => 'EditURI',
3261                                 'type' => 'application/rsd+xml',
3262                                 // Output a protocol-relative URL here if $wgServer is protocol-relative.
3263                                 // Whether RSD accepts relative or protocol-relative URLs is completely
3264                                 // undocumented, though.
3265                                 'href' => wfExpandUrl( wfAppendQuery(
3266                                         wfScript( 'api' ),
3267                                         [ 'action' => 'rsd' ] ),
3268                                         PROTO_RELATIVE
3269                                 ),
3270                         ] );
3271                 }
3272
3273                 # Language variants
3274                 if ( !$config->get( 'DisableLangConversion' ) ) {
3275                         $lang = $this->getTitle()->getPageLanguage();
3276                         if ( $lang->hasVariants() ) {
3277                                 $variants = $lang->getVariants();
3278                                 foreach ( $variants as $variant ) {
3279                                         $tags["variant-$variant"] = Html::element( 'link', [
3280                                                 'rel' => 'alternate',
3281                                                 'hreflang' => wfBCP47( $variant ),
3282                                                 'href' => $this->getTitle()->getLocalURL(
3283                                                         [ 'variant' => $variant ] )
3284                                                 ]
3285                                         );
3286                                 }
3287                                 # x-default link per https://support.google.com/webmasters/answer/189077?hl=en
3288                                 $tags["variant-x-default"] = Html::element( 'link', [
3289                                         'rel' => 'alternate',
3290                                         'hreflang' => 'x-default',
3291                                         'href' => $this->getTitle()->getLocalURL() ] );
3292                         }
3293                 }
3294
3295                 # Copyright
3296                 if ( $this->copyrightUrl !== null ) {
3297                         $copyright = $this->copyrightUrl;
3298                 } else {
3299                         $copyright = '';
3300                         if ( $config->get( 'RightsPage' ) ) {
3301                                 $copy = Title::newFromText( $config->get( 'RightsPage' ) );
3302
3303                                 if ( $copy ) {
3304                                         $copyright = $copy->getLocalURL();
3305                                 }
3306                         }
3307
3308                         if ( !$copyright && $config->get( 'RightsUrl' ) ) {
3309                                 $copyright = $config->get( 'RightsUrl' );
3310                         }
3311                 }
3312
3313                 if ( $copyright ) {
3314                         $tags['copyright'] = Html::element( 'link', [
3315                                 'rel' => 'copyright',
3316                                 'href' => $copyright ]
3317                         );
3318                 }
3319
3320                 # Feeds
3321                 if ( $config->get( 'Feed' ) ) {
3322                         $feedLinks = [];
3323
3324                         foreach ( $this->getSyndicationLinks() as $format => $link ) {
3325                                 # Use the page name for the title.  In principle, this could
3326                                 # lead to issues with having the same name for different feeds
3327                                 # corresponding to the same page, but we can't avoid that at
3328                                 # this low a level.
3329
3330                                 $feedLinks[] = $this->feedLink(
3331                                         $format,
3332                                         $link,
3333                                         # Used messages: 'page-rss-feed' and 'page-atom-feed' (for an easier grep)
3334                                         $this->msg(
3335                                                 "page-{$format}-feed", $this->getTitle()->getPrefixedText()
3336                                         )->text()
3337                                 );
3338                         }
3339
3340                         # Recent changes feed should appear on every page (except recentchanges,
3341                         # that would be redundant). Put it after the per-page feed to avoid
3342                         # changing existing behavior. It's still available, probably via a
3343                         # menu in your browser. Some sites might have a different feed they'd
3344                         # like to promote instead of the RC feed (maybe like a "Recent New Articles"
3345                         # or "Breaking news" one). For this, we see if $wgOverrideSiteFeed is defined.
3346                         # If so, use it instead.
3347                         $sitename = $config->get( 'Sitename' );
3348                         if ( $config->get( 'OverrideSiteFeed' ) ) {
3349                                 foreach ( $config->get( 'OverrideSiteFeed' ) as $type => $feedUrl ) {
3350                                         // Note, this->feedLink escapes the url.
3351                                         $feedLinks[] = $this->feedLink(
3352                                                 $type,
3353                                                 $feedUrl,
3354                                                 $this->msg( "site-{$type}-feed", $sitename )->text()
3355                                         );
3356                                 }
3357                         } elseif ( !$this->getTitle()->isSpecial( 'Recentchanges' ) ) {
3358                                 $rctitle = SpecialPage::getTitleFor( 'Recentchanges' );
3359                                 foreach ( $config->get( 'AdvertisedFeedTypes' ) as $format ) {
3360                                         $feedLinks[] = $this->feedLink(
3361                                                 $format,
3362                                                 $rctitle->getLocalURL( [ 'feed' => $format ] ),
3363                                                 # For grep: 'site-rss-feed', 'site-atom-feed'
3364                                                 $this->msg( "site-{$format}-feed", $sitename )->text()
3365                                         );
3366                                 }
3367                         }
3368
3369                         # Allow extensions to change the list pf feeds. This hook is primarily for changing,
3370                         # manipulating or removing existing feed tags. If you want to add new feeds, you should
3371                         # use OutputPage::addFeedLink() instead.
3372                         Hooks::run( 'AfterBuildFeedLinks', [ &$feedLinks ] );
3373
3374                         $tags += $feedLinks;
3375                 }
3376
3377                 # Canonical URL
3378                 if ( $config->get( 'EnableCanonicalServerLink' ) ) {
3379                         if ( $canonicalUrl !== false ) {
3380                                 $canonicalUrl = wfExpandUrl( $canonicalUrl, PROTO_CANONICAL );
3381                         } else {
3382                                 if ( $this->isArticleRelated() ) {
3383                                         // This affects all requests where "setArticleRelated" is true. This is
3384                                         // typically all requests that show content (query title, curid, oldid, diff),
3385                                         // and all wikipage actions (edit, delete, purge, info, history etc.).
3386                                         // It does not apply to File pages and Special pages.
3387                                         // 'history' and 'info' actions address page metadata rather than the page
3388                                         // content itself, so they may not be canonicalized to the view page url.
3389                                         // TODO: this ought to be better encapsulated in the Action class.
3390                                         $action = Action::getActionName( $this->getContext() );
3391                                         if ( in_array( $action, [ 'history', 'info' ] ) ) {
3392                                                 $query = "action={$action}";
3393                                         } else {
3394                                                 $query = '';
3395                                         }
3396                                         $canonicalUrl = $this->getTitle()->getCanonicalURL( $query );
3397                                 } else {
3398                                         $reqUrl = $this->getRequest()->getRequestURL();
3399                                         $canonicalUrl = wfExpandUrl( $reqUrl, PROTO_CANONICAL );
3400                                 }
3401                         }
3402                 }
3403                 if ( $canonicalUrl !== false ) {
3404                         $tags[] = Html::element( 'link', [
3405                                 'rel' => 'canonical',
3406                                 'href' => $canonicalUrl
3407                         ] );
3408                 }
3409
3410                 return $tags;
3411         }
3412
3413         /**
3414          * @return string HTML tag links to be put in the header.
3415          * @deprecated since 1.24 Use OutputPage::headElement or if you have to,
3416          *   OutputPage::getHeadLinksArray directly.
3417          */
3418         public function getHeadLinks() {
3419                 wfDeprecated( __METHOD__, '1.24' );
3420                 return implode( "\n", $this->getHeadLinksArray() );
3421         }
3422
3423         /**
3424          * Generate a "<link rel/>" for a feed.
3425          *
3426          * @param string $type Feed type
3427          * @param string $url URL to the feed
3428          * @param string $text Value of the "title" attribute
3429          * @return string HTML fragment
3430          */
3431         private function feedLink( $type, $url, $text ) {
3432                 return Html::element( 'link', [
3433                         'rel' => 'alternate',
3434                         'type' => "application/$type+xml",
3435                         'title' => $text,
3436                         'href' => $url ]
3437                 );
3438         }
3439
3440         /**
3441          * Add a local or specified stylesheet, with the given media options.
3442          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3443          *
3444          * @param string $style URL to the file
3445          * @param string $media To specify a media type, 'screen', 'printable', 'handheld' or any.
3446          * @param string $condition For IE conditional comments, specifying an IE version
3447          * @param string $dir Set to 'rtl' or 'ltr' for direction-specific sheets
3448          */
3449         public function addStyle( $style, $media = '', $condition = '', $dir = '' ) {
3450                 $options = [];
3451                 if ( $media ) {
3452                         $options['media'] = $media;
3453                 }
3454                 if ( $condition ) {
3455                         $options['condition'] = $condition;
3456                 }
3457                 if ( $dir ) {
3458                         $options['dir'] = $dir;
3459                 }
3460                 $this->styles[$style] = $options;
3461         }
3462
3463         /**
3464          * Adds inline CSS styles
3465          * Internal use only. Use OutputPage::addModuleStyles() if possible.
3466          *
3467          * @param mixed $style_css Inline CSS
3468          * @param string $flip Set to 'flip' to flip the CSS if needed
3469          */
3470         public function addInlineStyle( $style_css, $flip = 'noflip' ) {
3471                 if ( $flip === 'flip' && $this->getLanguage()->isRTL() ) {
3472                         # If wanted, and the interface is right-to-left, flip the CSS
3473                         $style_css = CSSJanus::transform( $style_css, true, false );
3474                 }
3475                 $this->mInlineStyles .= Html::inlineStyle( $style_css );
3476         }
3477
3478         /**
3479          * Build exempt modules and legacy non-ResourceLoader styles.
3480          *
3481          * @return string|WrappedStringList HTML
3482          */
3483         protected function buildExemptModules() {
3484                 global $wgContLang;
3485
3486                 $resourceLoader = $this->getResourceLoader();
3487                 $chunks = [];
3488                 // Things that go after the ResourceLoaderDynamicStyles marker
3489                 $append = [];
3490
3491                 // Exempt 'user' styles module (may need 'excludepages' for live preview)
3492                 if ( $this->isUserCssPreview() ) {
3493                         $append[] = $this->makeResourceLoaderLink(
3494                                 'user.styles',
3495                                 ResourceLoaderModule::TYPE_STYLES,
3496                                 [ 'excludepage' => $this->getTitle()->getPrefixedDBkey() ]
3497                         );
3498
3499                         // Load the previewed CSS. Janus it if needed.
3500                         // User-supplied CSS is assumed to in the wiki's content language.
3501                         $previewedCSS = $this->getRequest()->getText( 'wpTextbox1' );
3502                         if ( $this->getLanguage()->getDir() !== $wgContLang->getDir() ) {
3503                                 $previewedCSS = CSSJanus::transform( $previewedCSS, true, false );
3504                         }
3505                         $append[] = Html::inlineStyle( $previewedCSS );
3506                 }
3507
3508                 // We want site, private and user styles to override dynamically added styles from
3509                 // general modules, but we want dynamically added styles to override statically added
3510                 // style modules. So the order has to be:
3511                 // - page style modules (formatted by ResourceLoaderClientHtml::getHeadHtml())
3512                 // - dynamically loaded styles (added by mw.loader before ResourceLoaderDynamicStyles)
3513                 // - ResourceLoaderDynamicStyles marker
3514                 // - site/private/user styles
3515
3516                 // Add legacy styles added through addStyle()/addInlineStyle() here
3517                 $chunks[] = implode( '', $this->buildCssLinksArray() ) . $this->mInlineStyles;
3518
3519                 $chunks[] = Html::element(
3520                         'meta',
3521                         [ 'name' => 'ResourceLoaderDynamicStyles', 'content' => '' ]
3522                 );
3523
3524                 foreach ( $this->rlExemptStyleModules as $group => $moduleNames ) {
3525                         $chunks[] = $this->makeResourceLoaderLink( $moduleNames,
3526                                 ResourceLoaderModule::TYPE_STYLES
3527                         );
3528                 }
3529
3530                 return self::combineWrappedStrings( array_merge( $chunks, $append ) );
3531         }
3532
3533         /**
3534          * @return array
3535          */
3536         public function buildCssLinksArray() {
3537                 $links = [];
3538
3539                 // Add any extension CSS
3540                 foreach ( $this->mExtStyles as $url ) {
3541                         $this->addStyle( $url );
3542                 }
3543                 $this->mExtStyles = [];
3544
3545                 foreach ( $this->styles as $file => $options ) {
3546                         $link = $this->styleLink( $file, $options );
3547                         if ( $link ) {
3548                                 $links[$file] = $link;
3549                         }
3550                 }
3551                 return $links;
3552         }
3553
3554         /**
3555          * Generate \<link\> tags for stylesheets
3556          *
3557          * @param string $style URL to the file
3558          * @param array $options Option, can contain 'condition', 'dir', 'media' keys
3559          * @return string HTML fragment
3560          */
3561         protected function styleLink( $style, array $options ) {
3562                 if ( isset( $options['dir'] ) ) {
3563                         if ( $this->getLanguage()->getDir() != $options['dir'] ) {
3564                                 return '';
3565                         }
3566                 }
3567
3568                 if ( isset( $options['media'] ) ) {
3569                         $media = self::transformCssMedia( $options['media'] );
3570                         if ( is_null( $media ) ) {
3571                                 return '';
3572                         }
3573                 } else {
3574                         $media = 'all';
3575                 }
3576
3577                 if ( substr( $style, 0, 1 ) == '/' ||
3578                         substr( $style, 0, 5 ) == 'http:' ||
3579                         substr( $style, 0, 6 ) == 'https:' ) {
3580                         $url = $style;
3581                 } else {
3582                         $config = $this->getConfig();
3583                         $url = $config->get( 'StylePath' ) . '/' . $style . '?' .
3584                                 $config->get( 'StyleVersion' );
3585                 }
3586
3587                 $link = Html::linkedStyle( $url, $media );
3588
3589                 if ( isset( $options['condition'] ) ) {
3590                         $condition = htmlspecialchars( $options['condition'] );
3591                         $link = "<!--[if $condition]>$link<![endif]-->";
3592                 }
3593                 return $link;
3594         }
3595
3596         /**
3597          * Transform path to web-accessible static resource.
3598          *
3599          * This is used to add a validation hash as query string.
3600          * This aids various behaviors:
3601          *
3602          * - Put long Cache-Control max-age headers on responses for improved
3603          *   cache performance.
3604          * - Get the correct version of a file as expected by the current page.
3605          * - Instantly get the updated version of a file after deployment.
3606          *
3607          * Avoid using this for urls included in HTML as otherwise clients may get different
3608          * versions of a resource when navigating the site depending on when the page was cached.
3609          * If changes to the url propagate, this is not a problem (e.g. if the url is in
3610          * an external stylesheet).
3611          *
3612          * @since 1.27
3613          * @param Config $config
3614          * @param string $path Path-absolute URL to file (from document root, must start with "/")
3615          * @return string URL
3616          */
3617         public static function transformResourcePath( Config $config, $path ) {
3618                 global $IP;
3619                 $remotePathPrefix = $config->get( 'ResourceBasePath' );
3620                 if ( $remotePathPrefix === '' ) {
3621                         // The configured base path is required to be empty string for
3622                         // wikis in the domain root
3623                         $remotePath = '/';
3624                 } else {
3625                         $remotePath = $remotePathPrefix;
3626                 }
3627                 if ( strpos( $path, $remotePath ) !== 0 ) {
3628                         // Path is outside wgResourceBasePath, ignore.
3629                         return $path;
3630                 }
3631                 $path = RelPath\getRelativePath( $path, $remotePath );
3632                 return self::transformFilePath( $remotePathPrefix, $IP, $path );
3633         }
3634
3635         /**
3636          * Utility method for transformResourceFilePath().
3637          *
3638          * Caller is responsible for ensuring the file exists. Emits a PHP warning otherwise.
3639          *
3640          * @since 1.27
3641          * @param string $remotePath URL path prefix that points to $localPath
3642          * @param string $localPath File directory exposed at $remotePath
3643          * @param string $file Path to target file relative to $localPath
3644          * @return string URL
3645          */
3646         public static function transformFilePath( $remotePathPrefix, $localPath, $file ) {
3647                 $hash = md5_file( "$localPath/$file" );
3648                 if ( $hash === false ) {
3649                         wfLogWarning( __METHOD__ . ": Failed to hash $localPath/$file" );
3650                         $hash = '';
3651                 }
3652                 return "$remotePathPrefix/$file?" . substr( $hash, 0, 5 );
3653         }
3654
3655         /**
3656          * Transform "media" attribute based on request parameters
3657          *
3658          * @param string $media Current value of the "media" attribute
3659          * @return string Modified value of the "media" attribute, or null to skip
3660          * this stylesheet
3661          */
3662         public static function transformCssMedia( $media ) {
3663                 global $wgRequest;
3664
3665                 // http://www.w3.org/TR/css3-mediaqueries/#syntax
3666                 $screenMediaQueryRegex = '/^(?:only\s+)?screen\b/i';
3667
3668                 // Switch in on-screen display for media testing
3669                 $switches = [
3670                         'printable' => 'print',
3671                         'handheld' => 'handheld',
3672                 ];
3673                 foreach ( $switches as $switch => $targetMedia ) {
3674                         if ( $wgRequest->getBool( $switch ) ) {
3675                                 if ( $media == $targetMedia ) {
3676                                         $media = '';
3677                                 } elseif ( preg_match( $screenMediaQueryRegex, $media ) === 1 ) {
3678                                         /* This regex will not attempt to understand a comma-separated media_query_list
3679                                          *
3680                                          * Example supported values for $media:
3681                                          * 'screen', 'only screen', 'screen and (min-width: 982px)' ),
3682                                          * Example NOT supported value for $media:
3683                                          * '3d-glasses, screen, print and resolution > 90dpi'
3684                                          *
3685                                          * If it's a print request, we never want any kind of screen stylesheets
3686                                          * If it's a handheld request (currently the only other choice with a switch),
3687                                          * we don't want simple 'screen' but we might want screen queries that
3688                                          * have a max-width or something, so we'll pass all others on and let the
3689                                          * client do the query.
3690                                          */
3691                                         if ( $targetMedia == 'print' || $media == 'screen' ) {
3692                                                 return null;
3693                                         }
3694                                 }
3695                         }
3696                 }
3697
3698                 return $media;
3699         }
3700
3701         /**
3702          * Add a wikitext-formatted message to the output.
3703          * This is equivalent to:
3704          *
3705          *    $wgOut->addWikiText( wfMessage( ... )->plain() )
3706          */
3707         public function addWikiMsg( /*...*/ ) {
3708                 $args = func_get_args();
3709                 $name = array_shift( $args );
3710                 $this->addWikiMsgArray( $name, $args );
3711         }
3712
3713         /**
3714          * Add a wikitext-formatted message to the output.
3715          * Like addWikiMsg() except the parameters are taken as an array
3716          * instead of a variable argument list.
3717          *
3718          * @param string $name
3719          * @param array $args
3720          */
3721         public function addWikiMsgArray( $name, $args ) {
3722                 $this->addHTML( $this->msg( $name, $args )->parseAsBlock() );
3723         }
3724
3725         /**
3726          * This function takes a number of message/argument specifications, wraps them in
3727          * some overall structure, and then parses the result and adds it to the output.
3728          *
3729          * In the $wrap, $1 is replaced with the first message, $2 with the second,
3730          * and so on. The subsequent arguments may be either
3731          * 1) strings, in which case they are message names, or
3732          * 2) arrays, in which case, within each array, the first element is the message
3733          *    name, and subsequent elements are the parameters to that message.
3734          *
3735          * Don't use this for messages that are not in the user's interface language.
3736          *
3737          * For example:
3738          *
3739          *    $wgOut->wrapWikiMsg( "<div class='error'>\n$1\n</div>", 'some-error' );
3740          *
3741          * Is equivalent to:
3742          *
3743          *    $wgOut->addWikiText( "<div class='error'>\n"
3744          *        . wfMessage( 'some-error' )->plain() . "\n</div>" );
3745          *
3746          * The newline after the opening div is needed in some wikitext. See bug 19226.
3747          *
3748          * @param string $wrap
3749          */
3750         public function wrapWikiMsg( $wrap /*, ...*/ ) {
3751                 $msgSpecs = func_get_args();
3752                 array_shift( $msgSpecs );
3753                 $msgSpecs = array_values( $msgSpecs );
3754                 $s = $wrap;
3755                 foreach ( $msgSpecs as $n => $spec ) {
3756                         if ( is_array( $spec ) ) {
3757                                 $args = $spec;
3758                                 $name = array_shift( $args );
3759                                 if ( isset( $args['options'] ) ) {
3760                                         unset( $args['options'] );
3761                                         wfDeprecated(
3762                                                 'Adding "options" to ' . __METHOD__ . ' is no longer supported',
3763                                                 '1.20'
3764                                         );
3765                                 }
3766                         } else {
3767                                 $args = [];
3768                                 $name = $spec;
3769                         }
3770                         $s = str_replace( '$' . ( $n + 1 ), $this->msg( $name, $args )->plain(), $s );
3771                 }
3772                 $this->addWikiText( $s );
3773         }
3774
3775         /**
3776          * Enables/disables TOC, doesn't override __NOTOC__
3777          * @param bool $flag
3778          * @since 1.22
3779          */
3780         public function enableTOC( $flag = true ) {
3781                 $this->mEnableTOC = $flag;
3782         }
3783
3784         /**
3785          * @return bool
3786          * @since 1.22
3787          */
3788         public function isTOCEnabled() {
3789                 return $this->mEnableTOC;
3790         }
3791
3792         /**
3793          * Enables/disables section edit links, doesn't override __NOEDITSECTION__
3794          * @param bool $flag
3795          * @since 1.23
3796          */
3797         public function enableSectionEditLinks( $flag = true ) {
3798                 $this->mEnableSectionEditLinks = $flag;
3799         }
3800
3801         /**
3802          * @return bool
3803          * @since 1.23
3804          */
3805         public function sectionEditLinksEnabled() {
3806                 return $this->mEnableSectionEditLinks;
3807         }
3808
3809         /**
3810          * Helper function to setup the PHP implementation of OOUI to use in this request.
3811          *
3812          * @since 1.26
3813          * @param String $skinName The Skin name to determine the correct OOUI theme
3814          * @param String $dir Language direction
3815          */
3816         public static function setupOOUI( $skinName = '', $dir = 'ltr' ) {
3817                 $themes = ExtensionRegistry::getInstance()->getAttribute( 'SkinOOUIThemes' );
3818                 // Make keys (skin names) lowercase for case-insensitive matching.
3819                 $themes = array_change_key_case( $themes, CASE_LOWER );
3820                 $theme = isset( $themes[$skinName] ) ? $themes[$skinName] : 'MediaWiki';
3821                 // For example, 'OOUI\MediaWikiTheme'.
3822                 $themeClass = "OOUI\\{$theme}Theme";
3823                 OOUI\Theme::setSingleton( new $themeClass() );
3824                 OOUI\Element::setDefaultDir( $dir );
3825         }
3826
3827         /**
3828          * Add ResourceLoader module styles for OOUI and set up the PHP implementation of it for use with
3829          * MediaWiki and this OutputPage instance.
3830          *
3831          * @since 1.25
3832          */
3833         public function enableOOUI() {
3834                 self::setupOOUI(
3835                         strtolower( $this->getSkin()->getSkinName() ),
3836                         $this->getLanguage()->getDir()
3837                 );
3838                 $this->addModuleStyles( [
3839                         'oojs-ui-core.styles',
3840                         'oojs-ui.styles.icons',
3841                         'oojs-ui.styles.indicators',
3842                         'oojs-ui.styles.textures',
3843                         'mediawiki.widgets.styles',
3844                 ] );
3845         }
3846
3847         /**
3848          * @param array $data Data from ParserOutput::getLimitReportData()
3849          * @since 1.28
3850          */
3851         public function setLimitReportData( array $data ) {
3852                 $this->limitReportData = $data;
3853         }
3854 }