includes/parser/ParserOutput.php

   1 <?php
   2
   3 /**
   4  * Output of the PHP parser.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  * http://www.gnu.org/copyleft/gpl.html
  20  *
  21  * @file
  22  * @ingroup Parser
  23  */
  24
  25 class ParserOutput extends CacheTime {
  26         /**
  27          * Feature flags to indicate to extensions that MediaWiki core supports and
  28          * uses getText() stateless transforms.
  29          */
  30         const SUPPORTS_STATELESS_TRANSFORMS = 1;
  31         const SUPPORTS_UNWRAP_TRANSFORM = 1;
  32
  33         /**
  34          * @var string|null $mText The output text
  35          */
  36         public $mText = null;
  37
  38         /**
  39          * @var array $mLanguageLinks List of the full text of language links,
  40          *  in the order they appear.
  41          */
  42         public $mLanguageLinks;
  43
  44         /**
  45          * @var array $mCategoriesMap of category names to sort keys
  46          */
  47         public $mCategories;
  48
  49         /**
  50          * @var array $mIndicators Page status indicators, usually displayed in top-right corner.
  51          */
  52         public $mIndicators = [];
  53
  54         /**
  55          * @var string $mTitleText Title text of the chosen language variant, as HTML.
  56          */
  57         public $mTitleText;
  58
  59         /**
  60          * @var array $mLinks 2-D map of NS/DBK to ID for the links in the document.
  61          *  ID=zero for broken.
  62          */
  63         public $mLinks = [];
  64
  65         /**
  66          * @var array $mTemplates 2-D map of NS/DBK to ID for the template references.
  67          *  ID=zero for broken.
  68          */
  69         public $mTemplates = [];
  70
  71         /**
  72          * @var array $mTemplateIds 2-D map of NS/DBK to rev ID for the template references.
  73          *  ID=zero for broken.
  74          */
  75         public $mTemplateIds = [];
  76
  77         /**
  78          * @var array $mImages DB keys of the images used, in the array key only
  79          */
  80         public $mImages = [];
  81
  82         /**
  83          * @var array $mFileSearchOptions DB keys of the images used mapped to sha1 and MW timestamp.
  84          */
  85         public $mFileSearchOptions = [];
  86
  87         /**
  88          * @var array $mExternalLinks External link URLs, in the key only.
  89          */
  90         public $mExternalLinks = [];
  91
  92         /**
  93          * @var array $mInterwikiLinks 2-D map of prefix/DBK (in keys only)
  94          *  for the inline interwiki links in the document.
  95          */
  96         public $mInterwikiLinks = [];
  97
  98         /**
  99          * @var bool $mNewSection Show a new section link?
 100          */
 101         public $mNewSection = false;
 102
 103         /**
 104          * @var bool $mHideNewSection Hide the new section link?
 105          */
 106         public $mHideNewSection = false;
 107
 108         /**
 109          * @var bool $mNoGallery No gallery on category page? (__NOGALLERY__).
 110          */
 111         public $mNoGallery = false;
 112
 113         /**
 114          * @var array $mHeadItems Items to put in the <head> section
 115          */
 116         public $mHeadItems = [];
 117
 118         /**
 119          * @var array $mModules Modules to be loaded by ResourceLoader
 120          */
 121         public $mModules = [];
 122
 123         /**
 124          * @var array $mModuleScripts Modules of which only the JS will be loaded by ResourceLoader.
 125          */
 126         public $mModuleScripts = [];
 127
 128         /**
 129          * @var array $mModuleStyles Modules of which only the CSSS will be loaded by ResourceLoader.
 130          */
 131         public $mModuleStyles = [];
 132
 133         /**
 134          * @var array $mJsConfigVars JavaScript config variable for mw.config combined with this page.
 135          */
 136         public $mJsConfigVars = [];
 137
 138         /**
 139          * @var array $mOutputHooks Hook tags as per $wgParserOutputHooks.
 140          */
 141         public $mOutputHooks = [];
 142
 143         /**
 144          * @var array $mWarnings Warning text to be returned to the user.
 145          *  Wikitext formatted, in the key only.
 146          */
 147         public $mWarnings = [];
 148
 149         /**
 150          * @var array $mSections Table of contents
 151          */
 152         public $mSections = [];
 153
 154         /**
 155          * @var array $mProperties Name/value pairs to be cached in the DB.
 156          */
 157         public $mProperties = [];
 158
 159         /**
 160          * @var string $mTOCHTML HTML of the TOC.
 161          */
 162         public $mTOCHTML = '';
 163
 164         /**
 165          * @var string $mTimestamp Timestamp of the revision.
 166          */
 167         public $mTimestamp;
 168
 169         /**
 170          * @var bool $mEnableOOUI Whether OOUI should be enabled.
 171          */
 172         public $mEnableOOUI = false;
 173
 174         /**
 175          * @var string $mIndexPolicy 'index' or 'noindex'?  Any other value will result in no change.
 176          */
 177         private $mIndexPolicy = '';
 178
 179         /**
 180          * @var true[] $mAccessedOptions List of ParserOptions (stored in the keys).
 181          */
 182         private $mAccessedOptions = [];
 183
 184         /**
 185          * @var array $mExtensionData extra data used by extensions.
 186          */
 187         private $mExtensionData = [];
 188
 189         /**
 190          * @var array $mLimitReportData Parser limit report data.
 191          */
 192         private $mLimitReportData = [];
 193
 194         /** @var array Parser limit report data for JSON */
 195         private $mLimitReportJSData = [];
 196
 197         /**
 198          * @var array $mParseStartTime Timestamps for getTimeSinceStart().
 199          */
 200         private $mParseStartTime = [];
 201
 202         /**
 203          * @var bool $mPreventClickjacking Whether to emit X-Frame-Options: DENY.
 204          */
 205         private $mPreventClickjacking = false;
 206
 207         /**
 208          * @var array $mFlags Generic flags.
 209          */
 210         private $mFlags = [];
 211
 212         /** @var int|null Assumed rev ID for {{REVISIONID}} if no revision is set */
 213         private $mSpeculativeRevId;
 214
 215         /** string CSS classes to use for the wrapping div, stored in the array keys.
 216          * If no class is given, no wrapper is added.
 217          */
 218         private $mWrapperDivClasses = [];
 219
 220         /** @var int Upper bound of expiry based on parse duration */
 221         private $mMaxAdaptiveExpiry = INF;
 222
 223         const EDITSECTION_REGEX =
 224                 '#<(?:mw:)?editsection page="(.*?)" section="(.*?)"(?:/>|>(.*?)(</(?:mw:)?editsection>))#s';
 225
 226         // finalizeAdaptiveCacheExpiry() uses TTL = MAX( m * PARSE_TIME + b, MIN_AR_TTL)
 227         // Current values imply that m=3933.333333 and b=-333.333333
 228         // See https://www.nngroup.com/articles/website-response-times/
 229         const PARSE_FAST_SEC = 0.100; // perceived "fast" page parse
 230         const PARSE_SLOW_SEC = 1.0; // perceived "slow" page parse
 231         const FAST_AR_TTL = 60; // adaptive TTL for "fast" pages
 232         const SLOW_AR_TTL = 3600; // adaptive TTL for "slow" pages
 233         const MIN_AR_TTL = 15; // min adaptive TTL (for sanity, pool counter, and edit stashing)
 234
 235         /**
 236          * @param string|null $text HTML. Use null to indicate that this ParserOutput contains only
 237          *        meta-data, and the HTML output is undetermined, as opposed to empty. Passing null
 238          *        here causes hasText() to return false.
 239          * @param array $languageLinks
 240          * @param array $categoryLinks
 241          * @param bool $unused
 242          * @param string $titletext
 243          */
 244         public function __construct( $text = '', $languageLinks = [], $categoryLinks = [],
 245                 $unused = false, $titletext = ''
 246         ) {
 247                 $this->mText = $text;
 248                 $this->mLanguageLinks = $languageLinks;
 249                 $this->mCategories = $categoryLinks;
 250                 $this->mTitleText = $titletext;
 251         }
 252
 253         /**
 254          * Returns true if text was passed to the constructor, or set using setText(). Returns false
 255          * if null was passed to the $text parameter of the constructor to indicate that this
 256          * ParserOutput only contains meta-data, and the HTML output is undetermined.
 257          *
 258          * @since 1.32
 259          *
 260          * @return bool Whether this ParserOutput contains rendered text. If this returns false, the
 261          *         ParserOutput contains meta-data only.
 262          */
 263         public function hasText() {
 264                 return ( $this->mText !== null );
 265         }
 266
 267         /**
 268          * Get the cacheable text with <mw:editsection> markers still in it. The
 269          * return value is suitable for writing back via setText() but is not valid
 270          * for display to the user.
 271          *
 272          * @return string
 273          * @since 1.27
 274          */
 275         public function getRawText() {
 276                 if ( $this->mText === null ) {
 277                         throw new LogicException( 'This ParserOutput contains no text!' );
 278                 }
 279
 280                 return $this->mText;
 281         }
 282
 283         /**
 284          * Get the output HTML
 285          *
 286          * @param array $options (since 1.31) Transformations to apply to the HTML
 287          *  - allowTOC: (bool) Show the TOC, assuming there were enough headings
 288          *     to generate one and `__NOTOC__` wasn't used. Default is true,
 289          *     but might be statefully overridden.
 290          *  - enableSectionEditLinks: (bool) Include section edit links, assuming
 291          *     section edit link tokens are present in the HTML. Default is true,
 292          *     but might be statefully overridden.
 293          *  - unwrap: (bool) Return text without a wrapper div. Default is false,
 294          *    meaning a wrapper div will be added if getWrapperDivClass() returns
 295          *    a non-empty string.
 296          *  - wrapperDivClass: (string) Wrap the output in a div and apply the given
 297          *    CSS class to that div. This overrides the output of getWrapperDivClass().
 298          *    Setting this to an empty string has the same effect as 'unwrap' => true.
 299          *  - deduplicateStyles: (bool) When true, which is the default, `<style>`
 300          *    tags with the `data-mw-deduplicate` attribute set are deduplicated by
 301          *    value of the attribute: all but the first will be replaced by `<link
 302          *    rel="mw-deduplicated-inline-style" href="mw-data:..."/>` tags, where
 303          *    the scheme-specific-part of the href is the (percent-encoded) value
 304          *    of the `data-mw-deduplicate` attribute.
 305          * @return string HTML
 306          */
 307         public function getText( $options = [] ) {
 308                 $options += [
 309                         'allowTOC' => true,
 310                         'enableSectionEditLinks' => true,
 311                         'unwrap' => false,
 312                         'deduplicateStyles' => true,
 313                         'wrapperDivClass' => $this->getWrapperDivClass(),
 314                 ];
 315                 $text = $this->getRawText();
 316
 317                 Hooks::runWithoutAbort( 'ParserOutputPostCacheTransform', [ $this, &$text, &$options ] );
 318
 319                 if ( $options['wrapperDivClass'] !== '' && !$options['unwrap'] ) {
 320                         $text = Html::rawElement( 'div', [ 'class' => $options['wrapperDivClass'] ], $text );
 321                 }
 322
 323                 if ( $options['enableSectionEditLinks'] ) {
 324                         $text = preg_replace_callback(
 325                                 self::EDITSECTION_REGEX,
 326                                 function ( $m ) {
 327                                         global $wgOut, $wgLang;
 328                                         $editsectionPage = Title::newFromText( htmlspecialchars_decode( $m[1] ) );
 329                                         $editsectionSection = htmlspecialchars_decode( $m[2] );
 330                                         $editsectionContent = isset( $m[4] ) ? Sanitizer::decodeCharReferences( $m[3] ) : null;
 331
 332                                         if ( !is_object( $editsectionPage ) ) {
 333                                                 throw new MWException( "Bad parser output text." );
 334                                         }
 335
 336                                         $skin = $wgOut->getSkin();
 337                                         return $skin->doEditSectionLink( $editsectionPage,
 338                                                 $editsectionSection,
 339                                                 $editsectionContent,
 340                                                 $wgLang->getCode()
 341                                         );
 342                                 },
 343                                 $text
 344                         );
 345                 } else {
 346                         $text = preg_replace( self::EDITSECTION_REGEX, '', $text );
 347                 }
 348
 349                 if ( $options['allowTOC'] ) {
 350                         $text = str_replace( [ Parser::TOC_START, Parser::TOC_END ], '', $text );
 351                 } else {
 352                         $text = preg_replace(
 353                                 '#' . preg_quote( Parser::TOC_START, '#' ) . '.*?' . preg_quote( Parser::TOC_END, '#' ) . '#s',
 354                                 '',
 355                                 $text
 356                         );
 357                 }
 358
 359                 if ( $options['deduplicateStyles'] ) {
 360                         $seen = [];
 361                         $text = preg_replace_callback(
 362                                 '#<style\s+([^>]*data-mw-deduplicate\s*=[^>]*)>.*?</style>#s',
 363                                 function ( $m ) use ( &$seen ) {
 364                                         $attr = Sanitizer::decodeTagAttributes( $m[1] );
 365                                         if ( !isset( $attr['data-mw-deduplicate'] ) ) {
 366                                                 return $m[0];
 367                                         }
 368
 369                                         $key = $attr['data-mw-deduplicate'];
 370                                         if ( !isset( $seen[$key] ) ) {
 371                                                 $seen[$key] = true;
 372                                                 return $m[0];
 373                                         }
 374
 375                                         // We were going to use an empty <style> here, but there
 376                                         // was concern that would be too much overhead for browsers.
 377                                         // So let's hope a <link> with a non-standard rel and href isn't
 378                                         // going to be misinterpreted or mangled by any subsequent processing.
 379                                         return Html::element( 'link', [
 380                                                 'rel' => 'mw-deduplicated-inline-style',
 381                                                 'href' => "mw-data:" . wfUrlencode( $key ),
 382                                         ] );
 383                                 },
 384                                 $text
 385                         );
 386                 }
 387
 388                 // Hydrate slot section header placeholders generated by RevisionRenderer.
 389                 $text = preg_replace_callback(
 390                         '#<mw:slotheader>(.*?)</mw:slotheader>#',
 391                         function ( $m ) {
 392                                 $role = htmlspecialchars_decode( $m[1] );
 393                                 // TODO: map to message, using the interface language. Set lang="xyz" accordingly.
 394                                 $headerText = $role;
 395                                 return $headerText;
 396                         },
 397                         $text
 398                 );
 399                 return $text;
 400         }
 401
 402         /**
 403          * Add a CSS class to use for the wrapping div. If no class is given, no wrapper is added.
 404          *
 405          * @param string $class
 406          */
 407         public function addWrapperDivClass( $class ) {
 408                 $this->mWrapperDivClasses[$class] = true;
 409         }
 410
 411         /**
 412          * Clears the CSS class to use for the wrapping div, effectively disabling the wrapper div
 413          * until addWrapperDivClass() is called.
 414          */
 415         public function clearWrapperDivClass() {
 416                 $this->mWrapperDivClasses = [];
 417         }
 418
 419         /**
 420          * Returns the class (or classes) to be used with the wrapper div for this otuput.
 421          * If there is no wrapper class given, no wrapper div should be added.
 422          * The wrapper div is added automatically by getText().
 423          *
 424          * @return string
 425          */
 426         public function getWrapperDivClass() {
 427                 return implode( ' ', array_keys( $this->mWrapperDivClasses ) );
 428         }
 429
 430         /**
 431          * @param int $id
 432          * @since 1.28
 433          */
 434         public function setSpeculativeRevIdUsed( $id ) {
 435                 $this->mSpeculativeRevId = $id;
 436         }
 437
 438         /**
 439          * @return int|null
 440          * @since 1.28
 441          */
 442         public function getSpeculativeRevIdUsed() {
 443                 return $this->mSpeculativeRevId;
 444         }
 445
 446         public function &getLanguageLinks() {
 447                 return $this->mLanguageLinks;
 448         }
 449
 450         public function getInterwikiLinks() {
 451                 return $this->mInterwikiLinks;
 452         }
 453
 454         public function getCategoryLinks() {
 455                 return array_keys( $this->mCategories );
 456         }
 457
 458         public function &getCategories() {
 459                 return $this->mCategories;
 460         }
 461
 462         /**
 463          * @return array
 464          * @since 1.25
 465          */
 466         public function getIndicators() {
 467                 return $this->mIndicators;
 468         }
 469
 470         public function getTitleText() {
 471                 return $this->mTitleText;
 472         }
 473
 474         public function getSections() {
 475                 return $this->mSections;
 476         }
 477
 478         /**
 479          * @deprecated since 1.31 Use getText() options.
 480          */
 481         public function getEditSectionTokens() {
 482                 wfDeprecated( __METHOD__, '1.31' );
 483                 return true;
 484         }
 485
 486         public function &getLinks() {
 487                 return $this->mLinks;
 488         }
 489
 490         public function &getTemplates() {
 491                 return $this->mTemplates;
 492         }
 493
 494         public function &getTemplateIds() {
 495                 return $this->mTemplateIds;
 496         }
 497
 498         public function &getImages() {
 499                 return $this->mImages;
 500         }
 501
 502         public function &getFileSearchOptions() {
 503                 return $this->mFileSearchOptions;
 504         }
 505
 506         public function &getExternalLinks() {
 507                 return $this->mExternalLinks;
 508         }
 509
 510         public function setNoGallery( $value ) {
 511                 $this->mNoGallery = (bool)$value;
 512         }
 513         public function getNoGallery() {
 514                 return $this->mNoGallery;
 515         }
 516
 517         public function getHeadItems() {
 518                 return $this->mHeadItems;
 519         }
 520
 521         public function getModules() {
 522                 return $this->mModules;
 523         }
 524
 525         public function getModuleScripts() {
 526                 return $this->mModuleScripts;
 527         }
 528
 529         public function getModuleStyles() {
 530                 return $this->mModuleStyles;
 531         }
 532
 533         /**
 534          * @return array
 535          * @since 1.23
 536          */
 537         public function getJsConfigVars() {
 538                 return $this->mJsConfigVars;
 539         }
 540
 541         public function getOutputHooks() {
 542                 return (array)$this->mOutputHooks;
 543         }
 544
 545         public function getWarnings() {
 546                 return array_keys( $this->mWarnings );
 547         }
 548
 549         public function getIndexPolicy() {
 550                 return $this->mIndexPolicy;
 551         }
 552
 553         public function getTOCHTML() {
 554                 return $this->mTOCHTML;
 555         }
 556
 557         /**
 558          * @return string|null TS_MW timestamp of the revision content
 559          */
 560         public function getTimestamp() {
 561                 return $this->mTimestamp;
 562         }
 563
 564         public function getLimitReportData() {
 565                 return $this->mLimitReportData;
 566         }
 567
 568         public function getLimitReportJSData() {
 569                 return $this->mLimitReportJSData;
 570         }
 571
 572         /**
 573          * @deprecated since 1.31 Use getText() options.
 574          */
 575         public function getTOCEnabled() {
 576                 wfDeprecated( __METHOD__, '1.31' );
 577                 return true;
 578         }
 579
 580         public function getEnableOOUI() {
 581                 return $this->mEnableOOUI;
 582         }
 583
 584         public function setText( $text ) {
 585                 return wfSetVar( $this->mText, $text );
 586         }
 587
 588         public function setLanguageLinks( $ll ) {
 589                 return wfSetVar( $this->mLanguageLinks, $ll );
 590         }
 591
 592         public function setCategoryLinks( $cl ) {
 593                 return wfSetVar( $this->mCategories, $cl );
 594         }
 595
 596         public function setTitleText( $t ) {
 597                 return wfSetVar( $this->mTitleText, $t );
 598         }
 599
 600         public function setSections( $toc ) {
 601                 return wfSetVar( $this->mSections, $toc );
 602         }
 603
 604         /**
 605          * @deprecated since 1.31 Use getText() options.
 606          */
 607         public function setEditSectionTokens( $t ) {
 608                 wfDeprecated( __METHOD__, '1.31' );
 609                 return true;
 610         }
 611
 612         public function setIndexPolicy( $policy ) {
 613                 return wfSetVar( $this->mIndexPolicy, $policy );
 614         }
 615
 616         public function setTOCHTML( $tochtml ) {
 617                 return wfSetVar( $this->mTOCHTML, $tochtml );
 618         }
 619
 620         public function setTimestamp( $timestamp ) {
 621                 return wfSetVar( $this->mTimestamp, $timestamp );
 622         }
 623
 624         /**
 625          * @deprecated since 1.31 Use getText() options.
 626          */
 627         public function setTOCEnabled( $flag ) {
 628                 wfDeprecated( __METHOD__, '1.31' );
 629                 return true;
 630         }
 631
 632         public function addCategory( $c, $sort ) {
 633                 $this->mCategories[$c] = $sort;
 634         }
 635
 636         /**
 637          * @param string $id
 638          * @param string $content
 639          * @since 1.25
 640          */
 641         public function setIndicator( $id, $content ) {
 642                 $this->mIndicators[$id] = $content;
 643         }
 644
 645         /**
 646          * Enables OOUI, if true, in any OutputPage instance this ParserOutput
 647          * object is added to.
 648          *
 649          * @since 1.26
 650          * @param bool $enable If OOUI should be enabled or not
 651          */
 652         public function setEnableOOUI( $enable = false ) {
 653                 $this->mEnableOOUI = $enable;
 654         }
 655
 656         public function addLanguageLink( $t ) {
 657                 $this->mLanguageLinks[] = $t;
 658         }
 659
 660         public function addWarning( $s ) {
 661                 $this->mWarnings[$s] = 1;
 662         }
 663
 664         public function addOutputHook( $hook, $data = false ) {
 665                 $this->mOutputHooks[] = [ $hook, $data ];
 666         }
 667
 668         public function setNewSection( $value ) {
 669                 $this->mNewSection = (bool)$value;
 670         }
 671         public function hideNewSection( $value ) {
 672                 $this->mHideNewSection = (bool)$value;
 673         }
 674         public function getHideNewSection() {
 675                 return (bool)$this->mHideNewSection;
 676         }
 677         public function getNewSection() {
 678                 return (bool)$this->mNewSection;
 679         }
 680
 681         /**
 682          * Checks, if a url is pointing to the own server
 683          *
 684          * @param string $internal The server to check against
 685          * @param string $url The url to check
 686          * @return bool
 687          */
 688         public static function isLinkInternal( $internal, $url ) {
 689                 return (bool)preg_match( '/^' .
 690                         # If server is proto relative, check also for http/https links
 691                         ( substr( $internal, 0, 2 ) === '//' ? '(?:https?:)?' : '' ) .
 692                         preg_quote( $internal, '/' ) .
 693                         # check for query/path/anchor or end of link in each case
 694                         '(?:[\?\/\#]|$)/i',
 695                         $url
 696                 );
 697         }
 698
 699         public function addExternalLink( $url ) {
 700                 # We don't register links pointing to our own server, unless... :-)
 701                 global $wgServer, $wgRegisterInternalExternals;
 702
 703                 # Replace unnecessary URL escape codes with the referenced character
 704                 # This prevents spammers from hiding links from the filters
 705                 $url = Parser::normalizeLinkUrl( $url );
 706
 707                 $registerExternalLink = true;
 708                 if ( !$wgRegisterInternalExternals ) {
 709                         $registerExternalLink = !self::isLinkInternal( $wgServer, $url );
 710                 }
 711                 if ( $registerExternalLink ) {
 712                         $this->mExternalLinks[$url] = 1;
 713                 }
 714         }
 715
 716         /**
 717          * Record a local or interwiki inline link for saving in future link tables.
 718          *
 719          * @param Title $title
 720          * @param int|null $id Optional known page_id so we can skip the lookup
 721          */
 722         public function addLink( Title $title, $id = null ) {
 723                 if ( $title->isExternal() ) {
 724                         // Don't record interwikis in pagelinks
 725                         $this->addInterwikiLink( $title );
 726                         return;
 727                 }
 728                 $ns = $title->getNamespace();
 729                 $dbk = $title->getDBkey();
 730                 if ( $ns == NS_MEDIA ) {
 731                         // Normalize this pseudo-alias if it makes it down here...
 732                         $ns = NS_FILE;
 733                 } elseif ( $ns == NS_SPECIAL ) {
 734                         // We don't record Special: links currently
 735                         // It might actually be wise to, but we'd need to do some normalization.
 736                         return;
 737                 } elseif ( $dbk === '' ) {
 738                         // Don't record self links -  [[#Foo]]
 739                         return;
 740                 }
 741                 if ( !isset( $this->mLinks[$ns] ) ) {
 742                         $this->mLinks[$ns] = [];
 743                 }
 744                 if ( is_null( $id ) ) {
 745                         $id = $title->getArticleID();
 746                 }
 747                 $this->mLinks[$ns][$dbk] = $id;
 748         }
 749
 750         /**
 751          * Register a file dependency for this output
 752          * @param string $name Title dbKey
 753          * @param string|false|null $timestamp MW timestamp of file creation (or false if non-existing)
 754          * @param string|false|null $sha1 Base 36 SHA-1 of file (or false if non-existing)
 755          */
 756         public function addImage( $name, $timestamp = null, $sha1 = null ) {
 757                 $this->mImages[$name] = 1;
 758                 if ( $timestamp !== null && $sha1 !== null ) {
 759                         $this->mFileSearchOptions[$name] = [ 'time' => $timestamp, 'sha1' => $sha1 ];
 760                 }
 761         }
 762
 763         /**
 764          * Register a template dependency for this output
 765          * @param Title $title
 766          * @param int $page_id
 767          * @param int $rev_id
 768          */
 769         public function addTemplate( $title, $page_id, $rev_id ) {
 770                 $ns = $title->getNamespace();
 771                 $dbk = $title->getDBkey();
 772                 if ( !isset( $this->mTemplates[$ns] ) ) {
 773                         $this->mTemplates[$ns] = [];
 774                 }
 775                 $this->mTemplates[$ns][$dbk] = $page_id;
 776                 if ( !isset( $this->mTemplateIds[$ns] ) ) {
 777                         $this->mTemplateIds[$ns] = [];
 778                 }
 779                 $this->mTemplateIds[$ns][$dbk] = $rev_id; // For versioning
 780         }
 781
 782         /**
 783          * @param Title $title Title object, must be an interwiki link
 784          * @throws MWException If given invalid input
 785          */
 786         public function addInterwikiLink( $title ) {
 787                 if ( !$title->isExternal() ) {
 788                         throw new MWException( 'Non-interwiki link passed, internal parser error.' );
 789                 }
 790                 $prefix = $title->getInterwiki();
 791                 if ( !isset( $this->mInterwikiLinks[$prefix] ) ) {
 792                         $this->mInterwikiLinks[$prefix] = [];
 793                 }
 794                 $this->mInterwikiLinks[$prefix][$title->getDBkey()] = 1;
 795         }
 796
 797         /**
 798          * Add some text to the "<head>".
 799          * If $tag is set, the section with that tag will only be included once
 800          * in a given page.
 801          * @param string $section
 802          * @param string|bool $tag
 803          */
 804         public function addHeadItem( $section, $tag = false ) {
 805                 if ( $tag !== false ) {
 806                         $this->mHeadItems[$tag] = $section;
 807                 } else {
 808                         $this->mHeadItems[] = $section;
 809                 }
 810         }
 811
 812         /**
 813          * @see OutputPage::addModules
 814          */
 815         public function addModules( $modules ) {
 816                 $this->mModules = array_merge( $this->mModules, (array)$modules );
 817         }
 818
 819         /**
 820          * @deprecated since 1.31 Use addModules() instead.
 821          * @see OutputPage::addModuleScripts
 822          */
 823         public function addModuleScripts( $modules ) {
 824                 $this->mModuleScripts = array_merge( $this->mModuleScripts, (array)$modules );
 825         }
 826
 827         /**
 828          * @see OutputPage::addModuleStyles
 829          */
 830         public function addModuleStyles( $modules ) {
 831                 $this->mModuleStyles = array_merge( $this->mModuleStyles, (array)$modules );
 832         }
 833
 834         /**
 835          * Add one or more variables to be set in mw.config in JavaScript.
 836          *
 837          * @param string|array $keys Key or array of key/value pairs.
 838          * @param mixed|null $value [optional] Value of the configuration variable.
 839          * @since 1.23
 840          */
 841         public function addJsConfigVars( $keys, $value = null ) {
 842                 if ( is_array( $keys ) ) {
 843                         foreach ( $keys as $key => $value ) {
 844                                 $this->mJsConfigVars[$key] = $value;
 845                         }
 846                         return;
 847                 }
 848
 849                 $this->mJsConfigVars[$keys] = $value;
 850         }
 851
 852         /**
 853          * Copy items from the OutputPage object into this one
 854          *
 855          * @param OutputPage $out
 856          */
 857         public function addOutputPageMetadata( OutputPage $out ) {
 858                 $this->addModules( $out->getModules() );
 859                 $this->addModuleScripts( $out->getModuleScripts() );
 860                 $this->addModuleStyles( $out->getModuleStyles() );
 861                 $this->addJsConfigVars( $out->getJsConfigVars() );
 862
 863                 $this->mHeadItems = array_merge( $this->mHeadItems, $out->getHeadItemsArray() );
 864                 $this->mPreventClickjacking = $this->mPreventClickjacking || $out->getPreventClickjacking();
 865         }
 866
 867         /**
 868          * Add a tracking category, getting the title from a system message,
 869          * or print a debug message if the title is invalid.
 870          *
 871          * Any message used with this function should be registered so it will
 872          * show up on Special:TrackingCategories. Core messages should be added
 873          * to SpecialTrackingCategories::$coreTrackingCategories, and extensions
 874          * should add to "TrackingCategories" in their extension.json.
 875          *
 876          * @todo Migrate some code to TrackingCategories
 877          *
 878          * @param string $msg Message key
 879          * @param Title $title title of the page which is being tracked
 880          * @return bool Whether the addition was successful
 881          * @since 1.25
 882          */
 883         public function addTrackingCategory( $msg, $title ) {
 884                 if ( $title->isSpecialPage() ) {
 885                         wfDebug( __METHOD__ . ": Not adding tracking category $msg to special page!\n" );
 886                         return false;
 887                 }
 888
 889                 // Important to parse with correct title (T33469)
 890                 $cat = wfMessage( $msg )
 891                         ->title( $title )
 892                         ->inContentLanguage()
 893                         ->text();
 894
 895                 # Allow tracking categories to be disabled by setting them to "-"
 896                 if ( $cat === '-' ) {
 897                         return false;
 898                 }
 899
 900                 $containerCategory = Title::makeTitleSafe( NS_CATEGORY, $cat );
 901                 if ( $containerCategory ) {
 902                         $this->addCategory( $containerCategory->getDBkey(), $this->getProperty( 'defaultsort' ) ?: '' );
 903                         return true;
 904                 } else {
 905                         wfDebug( __METHOD__ . ": [[MediaWiki:$msg]] is not a valid title!\n" );
 906                         return false;
 907                 }
 908         }
 909
 910         /**
 911          * Override the title to be used for display
 912          *
 913          * @note this is assumed to have been validated
 914          * (check equal normalisation, etc.)
 915          *
 916          * @note this is expected to be safe HTML,
 917          * ready to be served to the client.
 918          *
 919          * @param string $text Desired title text
 920          */
 921         public function setDisplayTitle( $text ) {
 922                 $this->setTitleText( $text );
 923                 $this->setProperty( 'displaytitle', $text );
 924         }
 925
 926         /**
 927          * Get the title to be used for display.
 928          *
 929          * As per the contract of setDisplayTitle(), this is safe HTML,
 930          * ready to be served to the client.
 931          *
 932          * @return string HTML
 933          */
 934         public function getDisplayTitle() {
 935                 $t = $this->getTitleText();
 936                 if ( $t === '' ) {
 937                         return false;
 938                 }
 939                 return $t;
 940         }
 941
 942         /**
 943          * Fairly generic flag setter thingy.
 944          * @param string $flag
 945          */
 946         public function setFlag( $flag ) {
 947                 $this->mFlags[$flag] = true;
 948         }
 949
 950         public function getFlag( $flag ) {
 951                 return isset( $this->mFlags[$flag] );
 952         }
 953
 954         /**
 955          * Set a property to be stored in the page_props database table.
 956          *
 957          * page_props is a key value store indexed by the page ID. This allows
 958          * the parser to set a property on a page which can then be quickly
 959          * retrieved given the page ID or via a DB join when given the page
 960          * title.
 961          *
 962          * Since 1.23, page_props are also indexed by numeric value, to allow
 963          * for efficient "top k" queries of pages wrt a given property.
 964          *
 965          * setProperty() is thus used to propagate properties from the parsed
 966          * page to request contexts other than a page view of the currently parsed
 967          * article.
 968          *
 969          * Some applications examples:
 970          *
 971          *   * To implement hidden categories, hiding pages from category listings
 972          *     by storing a property.
 973          *
 974          *   * Overriding the displayed article title (ParserOutput::setDisplayTitle()).
 975          *
 976          *   * To implement image tagging, for example displaying an icon on an
 977          *     image thumbnail to indicate that it is listed for deletion on
 978          *     Wikimedia Commons.
 979          *     This is not actually implemented, yet but would be pretty cool.
 980          *
 981          * @note Do not use setProperty() to set a property which is only used
 982          * in a context where the ParserOutput object itself is already available,
 983          * for example a normal page view. There is no need to save such a property
 984          * in the database since the text is already parsed. You can just hook
 985          * OutputPageParserOutput and get your data out of the ParserOutput object.
 986          *
 987          * If you are writing an extension where you want to set a property in the
 988          * parser which is used by an OutputPageParserOutput hook, you have to
 989          * associate the extension data directly with the ParserOutput object.
 990          * Since MediaWiki 1.21, you can use setExtensionData() to do this:
 991          *
 992          * @par Example:
 993          * @code
 994          *    $parser->getOutput()->setExtensionData( 'my_ext_foo', '...' );
 995          * @endcode
 996          *
 997          * And then later, in OutputPageParserOutput or similar:
 998          *
 999          * @par Example:
1000          * @code
1001          *    $output->getExtensionData( 'my_ext_foo' );
1002          * @endcode
1003          *
1004          * In MediaWiki 1.20 and older, you have to use a custom member variable
1005          * within the ParserOutput object:
1006          *
1007          * @par Example:
1008          * @code
1009          *    $parser->getOutput()->my_ext_foo = '...';
1010          * @endcode
1011          * @param string $name
1012          * @param mixed $value
1013          */
1014         public function setProperty( $name, $value ) {
1015                 $this->mProperties[$name] = $value;
1016         }
1017
1018         /**
1019          * @param string $name The property name to look up.
1020          *
1021          * @return mixed|bool The value previously set using setProperty(). False if null or no value
1022          * was set for the given property name.
1023          *
1024          * @note You need to use getProperties() to check for boolean and null properties.
1025          */
1026         public function getProperty( $name ) {
1027                 return $this->mProperties[$name] ?? false;
1028         }
1029
1030         public function unsetProperty( $name ) {
1031                 unset( $this->mProperties[$name] );
1032         }
1033
1034         public function getProperties() {
1035                 if ( !isset( $this->mProperties ) ) {
1036                         $this->mProperties = [];
1037                 }
1038                 return $this->mProperties;
1039         }
1040
1041         /**
1042          * Returns the options from its ParserOptions which have been taken
1043          * into account to produce this output.
1044          * @return string[]
1045          */
1046         public function getUsedOptions() {
1047                 if ( !isset( $this->mAccessedOptions ) ) {
1048                         return [];
1049                 }
1050                 return array_keys( $this->mAccessedOptions );
1051         }
1052
1053         /**
1054          * Tags a parser option for use in the cache key for this parser output.
1055          * Registered as a watcher at ParserOptions::registerWatcher() by Parser::clearState().
1056          * The information gathered here is available via getUsedOptions(),
1057          * and is used by ParserCache::save().
1058          *
1059          * @see ParserCache::getKey
1060          * @see ParserCache::save
1061          * @see ParserOptions::addExtraKey
1062          * @see ParserOptions::optionsHash
1063          * @param string $option
1064          */
1065         public function recordOption( $option ) {
1066                 $this->mAccessedOptions[$option] = true;
1067         }
1068
1069         /**
1070          * Attaches arbitrary data to this ParserObject. This can be used to store some information in
1071          * the ParserOutput object for later use during page output. The data will be cached along with
1072          * the ParserOutput object, but unlike data set using setProperty(), it is not recorded in the
1073          * database.
1074          *
1075          * This method is provided to overcome the unsafe practice of attaching extra information to a
1076          * ParserObject by directly assigning member variables.
1077          *
1078          * To use setExtensionData() to pass extension information from a hook inside the parser to a
1079          * hook in the page output, use this in the parser hook:
1080          *
1081          * @par Example:
1082          * @code
1083          *    $parser->getOutput()->setExtensionData( 'my_ext_foo', '...' );
1084          * @endcode
1085          *
1086          * And then later, in OutputPageParserOutput or similar:
1087          *
1088          * @par Example:
1089          * @code
1090          *    $output->getExtensionData( 'my_ext_foo' );
1091          * @endcode
1092          *
1093          * In MediaWiki 1.20 and older, you have to use a custom member variable
1094          * within the ParserOutput object:
1095          *
1096          * @par Example:
1097          * @code
1098          *    $parser->getOutput()->my_ext_foo = '...';
1099          * @endcode
1100          *
1101          * @since 1.21
1102          *
1103          * @param string $key The key for accessing the data. Extensions should take care to avoid
1104          *   conflicts in naming keys. It is suggested to use the extension's name as a prefix.
1105          *
1106          * @param mixed $value The value to set. Setting a value to null is equivalent to removing
1107          *   the value.
1108          */
1109         public function setExtensionData( $key, $value ) {
1110                 if ( $value === null ) {
1111                         unset( $this->mExtensionData[$key] );
1112                 } else {
1113                         $this->mExtensionData[$key] = $value;
1114                 }
1115         }
1116
1117         /**
1118          * Gets extensions data previously attached to this ParserOutput using setExtensionData().
1119          * Typically, such data would be set while parsing the page, e.g. by a parser function.
1120          *
1121          * @since 1.21
1122          *
1123          * @param string $key The key to look up.
1124          *
1125          * @return mixed|null The value previously set for the given key using setExtensionData()
1126          *         or null if no value was set for this key.
1127          */
1128         public function getExtensionData( $key ) {
1129                 if ( isset( $this->mExtensionData[$key] ) ) {
1130                         return $this->mExtensionData[$key];
1131                 }
1132
1133                 return null;
1134         }
1135
1136         private static function getTimes( $clock = null ) {
1137                 $ret = [];
1138                 if ( !$clock || $clock === 'wall' ) {
1139                         $ret['wall'] = microtime( true );
1140                 }
1141                 if ( !$clock || $clock === 'cpu' ) {
1142                         $ru = wfGetRusage();
1143                         if ( $ru ) {
1144                                 $ret['cpu'] = $ru['ru_utime.tv_sec'] + $ru['ru_utime.tv_usec'] / 1e6;
1145                                 $ret['cpu'] += $ru['ru_stime.tv_sec'] + $ru['ru_stime.tv_usec'] / 1e6;
1146                         }
1147                 }
1148                 return $ret;
1149         }
1150
1151         /**
1152          * Resets the parse start timestamps for future calls to getTimeSinceStart()
1153          * @since 1.22
1154          */
1155         public function resetParseStartTime() {
1156                 $this->mParseStartTime = self::getTimes();
1157         }
1158
1159         /**
1160          * Returns the time since resetParseStartTime() was last called
1161          *
1162          * Clocks available are:
1163          *  - wall: Wall clock time
1164          *  - cpu: CPU time (requires getrusage)
1165          *
1166          * @since 1.22
1167          * @param string $clock
1168          * @return float|null
1169          */
1170         public function getTimeSinceStart( $clock ) {
1171                 if ( !isset( $this->mParseStartTime[$clock] ) ) {
1172                         return null;
1173                 }
1174
1175                 $end = self::getTimes( $clock );
1176                 return $end[$clock] - $this->mParseStartTime[$clock];
1177         }
1178
1179         /**
1180          * Sets parser limit report data for a key
1181          *
1182          * The key is used as the prefix for various messages used for formatting:
1183          *  - $key: The label for the field in the limit report
1184          *  - $key-value-text: Message used to format the value in the "NewPP limit
1185          *      report" HTML comment. If missing, uses $key-format.
1186          *  - $key-value-html: Message used to format the value in the preview
1187          *      limit report table. If missing, uses $key-format.
1188          *  - $key-value: Message used to format the value. If missing, uses "$1".
1189          *
1190          * Note that all values are interpreted as wikitext, and so should be
1191          * encoded with htmlspecialchars() as necessary, but should avoid complex
1192          * HTML for sanity of display in the "NewPP limit report" comment.
1193          *
1194          * @since 1.22
1195          * @param string $key Message key
1196          * @param mixed $value Appropriate for Message::params()
1197          */
1198         public function setLimitReportData( $key, $value ) {
1199                 $this->mLimitReportData[$key] = $value;
1200
1201                 if ( is_array( $value ) ) {
1202                         if ( array_keys( $value ) === [ 0, 1 ]
1203                                 && is_numeric( $value[0] )
1204                                 && is_numeric( $value[1] )
1205                         ) {
1206                                 $data = [ 'value' => $value[0], 'limit' => $value[1] ];
1207                         } else {
1208                                 $data = $value;
1209                         }
1210                 } else {
1211                         $data = $value;
1212                 }
1213
1214                 if ( strpos( $key, '-' ) ) {
1215                         list( $ns, $name ) = explode( '-', $key, 2 );
1216                         $this->mLimitReportJSData[$ns][$name] = $data;
1217                 } else {
1218                         $this->mLimitReportJSData[$key] = $data;
1219                 }
1220         }
1221
1222         /**
1223          * Check whether the cache TTL was lowered due to dynamic content
1224          *
1225          * When content is determined by more than hard state (e.g. page edits),
1226          * such as template/file transclusions based on the current timestamp or
1227          * extension tags that generate lists based on queries, this return true.
1228          *
1229          * @return bool
1230          * @since 1.25
1231          */
1232         public function hasDynamicContent() {
1233                 global $wgParserCacheExpireTime;
1234
1235                 return $this->getCacheExpiry() < $wgParserCacheExpireTime;
1236         }
1237
1238         /**
1239          * Get or set the prevent-clickjacking flag
1240          *
1241          * @since 1.24
1242          * @param bool|null $flag New flag value, or null to leave it unchanged
1243          * @return bool Old flag value
1244          */
1245         public function preventClickjacking( $flag = null ) {
1246                 return wfSetVar( $this->mPreventClickjacking, $flag );
1247         }
1248
1249         /**
1250          * Lower the runtime adaptive TTL to at most this value
1251          *
1252          * @param int $ttl
1253          * @since 1.28
1254          */
1255         public function updateRuntimeAdaptiveExpiry( $ttl ) {
1256                 $this->mMaxAdaptiveExpiry = min( $ttl, $this->mMaxAdaptiveExpiry );
1257                 $this->updateCacheExpiry( $ttl );
1258         }
1259
1260         /**
1261          * Call this when parsing is done to lower the TTL based on low parse times
1262          *
1263          * @since 1.28
1264          */
1265         public function finalizeAdaptiveCacheExpiry() {
1266                 if ( is_infinite( $this->mMaxAdaptiveExpiry ) ) {
1267                         return; // not set
1268                 }
1269
1270                 $runtime = $this->getTimeSinceStart( 'wall' );
1271                 if ( is_float( $runtime ) ) {
1272                         $slope = ( self::SLOW_AR_TTL - self::FAST_AR_TTL )
1273                                 / ( self::PARSE_SLOW_SEC - self::PARSE_FAST_SEC );
1274                         // SLOW_AR_TTL = PARSE_SLOW_SEC * $slope + $point
1275                         $point = self::SLOW_AR_TTL - self::PARSE_SLOW_SEC * $slope;
1276
1277                         $adaptiveTTL = min(
1278                                 max( $slope * $runtime + $point, self::MIN_AR_TTL ),
1279                                 $this->mMaxAdaptiveExpiry
1280                         );
1281                         $this->updateCacheExpiry( $adaptiveTTL );
1282                 }
1283         }
1284
1285         public function __sleep() {
1286                 return array_diff(
1287                         array_keys( get_object_vars( $this ) ),
1288                         [ 'mParseStartTime' ]
1289                 );
1290         }
1291
1292         /**
1293          * Merges internal metadata such as flags, accessed options, and profiling info
1294          * from $source into this ParserOutput. This should be used whenever the state of $source
1295          * has any impact on the state of this ParserOutput.
1296          *
1297          * @param ParserOutput $source
1298          */
1299         public function mergeInternalMetaDataFrom( ParserOutput $source ) {
1300                 $this->mOutputHooks = self::mergeList( $this->mOutputHooks, $source->getOutputHooks() );
1301                 $this->mWarnings = self::mergeMap( $this->mWarnings, $source->mWarnings ); // don't use getter
1302                 $this->mTimestamp = $this->useMaxValue( $this->mTimestamp, $source->getTimestamp() );
1303
1304                 if ( $this->mSpeculativeRevId && $source->mSpeculativeRevId
1305                         && $this->mSpeculativeRevId !== $source->mSpeculativeRevId
1306                 ) {
1307                         wfLogWarning(
1308                                 'Inconsistent speculative revision ID encountered while merging parser output!'
1309                         );
1310                 }
1311
1312                 $this->mSpeculativeRevId = $this->useMaxValue(
1313                         $this->mSpeculativeRevId,
1314                         $source->getSpeculativeRevIdUsed()
1315                 );
1316                 $this->mParseStartTime = $this->useEachMinValue(
1317                         $this->mParseStartTime,
1318                         $source->mParseStartTime
1319                 );
1320
1321                 $this->mFlags = self::mergeMap( $this->mFlags, $source->mFlags );
1322                 $this->mAccessedOptions = self::mergeMap( $this->mAccessedOptions, $source->mAccessedOptions );
1323
1324                 // TODO: maintain per-slot limit reports!
1325                 if ( empty( $this->mLimitReportData ) ) {
1326                         $this->mLimitReportData = $source->mLimitReportData;
1327                 }
1328                 if ( empty( $this->mLimitReportJSData ) ) {
1329                         $this->mLimitReportJSData = $source->mLimitReportJSData;
1330                 }
1331         }
1332
1333         /**
1334          * Merges HTML metadata such as head items, JS config vars, and HTTP cache control info
1335          * from $source into this ParserOutput. This should be used whenever the HTML in $source
1336          * has been somehow mered into the HTML of this ParserOutput.
1337          *
1338          * @param ParserOutput $source
1339          */
1340         public function mergeHtmlMetaDataFrom( ParserOutput $source ) {
1341                 // HTML and HTTP
1342                 $this->mHeadItems = self::mergeMixedList( $this->mHeadItems, $source->getHeadItems() );
1343                 $this->mModules = self::mergeList( $this->mModules, $source->getModules() );
1344                 $this->mModuleScripts = self::mergeList( $this->mModuleScripts, $source->getModuleScripts() );
1345                 $this->mModuleStyles = self::mergeList( $this->mModuleStyles, $source->getModuleStyles() );
1346                 $this->mJsConfigVars = self::mergeMap( $this->mJsConfigVars, $source->getJsConfigVars() );
1347                 $this->mMaxAdaptiveExpiry = min( $this->mMaxAdaptiveExpiry, $source->mMaxAdaptiveExpiry );
1348
1349                 // "noindex" always wins!
1350                 if ( $this->mIndexPolicy === 'noindex' || $source->mIndexPolicy === 'noindex' ) {
1351                         $this->mIndexPolicy = 'noindex';
1352                 } elseif ( $this->mIndexPolicy !== 'index' ) {
1353                         $this->mIndexPolicy = $source->mIndexPolicy;
1354                 }
1355
1356                 // Skin control
1357                 $this->mNewSection = $this->mNewSection || $source->getNewSection();
1358                 $this->mHideNewSection = $this->mHideNewSection || $source->getHideNewSection();
1359                 $this->mNoGallery = $this->mNoGallery || $source->getNoGallery();
1360                 $this->mEnableOOUI = $this->mEnableOOUI || $source->getEnableOOUI();
1361                 $this->mPreventClickjacking = $this->mPreventClickjacking || $source->preventClickjacking();
1362
1363                 // TODO: we'll have to be smarter about this!
1364                 $this->mSections = array_merge( $this->mSections, $source->getSections() );
1365                 $this->mTOCHTML = $this->mTOCHTML . $source->mTOCHTML;
1366
1367                 // XXX: we don't want to concatenate title text, so first write wins.
1368                 // We should use the first *modified* title text, but we don't have the original to check.
1369                 if ( $this->mTitleText === null || $this->mTitleText === '' ) {
1370                         $this->mTitleText = $source->mTitleText;
1371                 }
1372
1373                 // class names are stored in array keys
1374                 $this->mWrapperDivClasses = self::mergeMap(
1375                         $this->mWrapperDivClasses,
1376                         $source->mWrapperDivClasses
1377                 );
1378
1379                 // NOTE: last write wins, same as within one ParserOutput
1380                 $this->mIndicators = self::mergeMap( $this->mIndicators, $source->getIndicators() );
1381
1382                 // NOTE: include extension data in "tracking meta data" as well as "html meta data"!
1383                 // TODO: add a $mergeStrategy parameter to setExtensionData to allow different
1384                 // kinds of extension data to be merged in different ways.
1385                 $this->mExtensionData = self::mergeMap(
1386                         $this->mExtensionData,
1387                         $source->mExtensionData
1388                 );
1389         }
1390
1391         /**
1392          * Merges dependency tracking metadata such as backlinks, images used, and extension data
1393          * from $source into this ParserOutput. This allows dependency tracking to be done for the
1394          * combined output of multiple content slots.
1395          *
1396          * @param ParserOutput $source
1397          */
1398         public function mergeTrackingMetaDataFrom( ParserOutput $source ) {
1399                 $this->mLanguageLinks = self::mergeList( $this->mLanguageLinks, $source->getLanguageLinks() );
1400                 $this->mCategories = self::mergeMap( $this->mCategories, $source->getCategories() );
1401                 $this->mLinks = self::merge2D( $this->mLinks, $source->getLinks() );
1402                 $this->mTemplates = self::merge2D( $this->mTemplates, $source->getTemplates() );
1403                 $this->mTemplateIds = self::merge2D( $this->mTemplateIds, $source->getTemplateIds() );
1404                 $this->mImages = self::mergeMap( $this->mImages, $source->getImages() );
1405                 $this->mFileSearchOptions = self::mergeMap(
1406                         $this->mFileSearchOptions,
1407                         $source->getFileSearchOptions()
1408                 );
1409                 $this->mExternalLinks = self::mergeMap( $this->mExternalLinks, $source->getExternalLinks() );
1410                 $this->mInterwikiLinks = self::merge2D(
1411                         $this->mInterwikiLinks,
1412                         $source->getInterwikiLinks()
1413                 );
1414
1415                 // TODO: add a $mergeStrategy parameter to setProperty to allow different
1416                 // kinds of properties to be merged in different ways.
1417                 $this->mProperties = self::mergeMap( $this->mProperties, $source->getProperties() );
1418
1419                 // NOTE: include extension data in "tracking meta data" as well as "html meta data"!
1420                 // TODO: add a $mergeStrategy parameter to setExtensionData to allow different
1421                 // kinds of extension data to be merged in different ways.
1422                 $this->mExtensionData = self::mergeMap(
1423                         $this->mExtensionData,
1424                         $source->mExtensionData
1425                 );
1426         }
1427
1428         private static function mergeMixedList( array $a, array $b ) {
1429                 return array_unique( array_merge( $a, $b ), SORT_REGULAR );
1430         }
1431
1432         private static function mergeList( array $a, array $b ) {
1433                 return array_values( array_unique( array_merge( $a, $b ), SORT_REGULAR ) );
1434         }
1435
1436         private static function mergeMap( array $a, array $b ) {
1437                 return array_replace( $a, $b );
1438         }
1439
1440         private static function merge2D( array $a, array $b ) {
1441                 $values = [];
1442                 $keys = array_merge( array_keys( $a ), array_keys( $b ) );
1443
1444                 foreach ( $keys as $k ) {
1445                         if ( empty( $a[$k] ) ) {
1446                                 $values[$k] = $b[$k];
1447                         } elseif ( empty( $b[$k] ) ) {
1448                                 $values[$k] = $a[$k];
1449                         } elseif ( is_array( $a[$k] ) && is_array( $b[$k] ) ) {
1450                                 $values[$k] = array_replace( $a[$k], $b[$k] );
1451                         } else {
1452                                 $values[$k] = $b[$k];
1453                         }
1454                 }
1455
1456                 return $values;
1457         }
1458
1459         private static function useEachMinValue( array $a, array $b ) {
1460                 $values = [];
1461                 $keys = array_merge( array_keys( $a ), array_keys( $b ) );
1462
1463                 foreach ( $keys as $k ) {
1464                         if ( is_array( $a[$k] ?? null ) && is_array( $b[$k] ?? null ) ) {
1465                                 $values[$k] = self::useEachMinValue( $a[$k], $b[$k] );
1466                         } else {
1467                                 $values[$k] = self::useMinValue( $a[$k] ?? null, $b[$k] ?? null );
1468                         }
1469                 }
1470
1471                 return $values;
1472         }
1473
1474         private static function useMinValue( $a, $b ) {
1475                 if ( $a === null ) {
1476                         return $b;
1477                 }
1478
1479                 if ( $b === null ) {
1480                         return $a;
1481                 }
1482
1483                 return min( $a, $b );
1484         }
1485
1486         private static function useMaxValue( $a, $b ) {
1487                 if ( $a === null ) {
1488                         return $b;
1489                 }
1490
1491                 if ( $b === null ) {
1492                         return $a;
1493                 }
1494
1495                 return max( $a, $b );
1496         }
1497
1498 }