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