includes/parser/LinkHolderArray.php

   1 <?php
   2 /**
   3  * Holder of replacement pairs for wiki links
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Parser
  22  */
  23
  24 /**
  25  * @ingroup Parser
  26  */
  27 class LinkHolderArray {
  28         public $internals = [];
  29         public $interwikis = [];
  30         public $size = 0;
  31
  32         /**
  33          * @var Parser
  34          */
  35         public $parent;
  36         protected $tempIdOffset;
  37
  38         /**
  39          * @param Parser $parent
  40          */
  41         public function __construct( $parent ) {
  42                 $this->parent = $parent;
  43         }
  44
  45         /**
  46          * Reduce memory usage to reduce the impact of circular references
  47          */
  48         public function __destruct() {
  49                 foreach ( $this as $name => $value ) {
  50                         unset( $this->$name );
  51                 }
  52         }
  53
  54         /**
  55          * Don't serialize the parent object, it is big, and not needed when it is
  56          * a parameter to mergeForeign(), which is the only application of
  57          * serializing at present.
  58          *
  59          * Compact the titles, only serialize the text form.
  60          * @return array
  61          */
  62         public function __sleep() {
  63                 foreach ( $this->internals as &$nsLinks ) {
  64                         foreach ( $nsLinks as &$entry ) {
  65                                 unset( $entry['title'] );
  66                         }
  67                 }
  68                 unset( $nsLinks );
  69                 unset( $entry );
  70
  71                 foreach ( $this->interwikis as &$entry ) {
  72                         unset( $entry['title'] );
  73                 }
  74                 unset( $entry );
  75
  76                 return [ 'internals', 'interwikis', 'size' ];
  77         }
  78
  79         /**
  80          * Recreate the Title objects
  81          */
  82         public function __wakeup() {
  83                 foreach ( $this->internals as &$nsLinks ) {
  84                         foreach ( $nsLinks as &$entry ) {
  85                                 $entry['title'] = Title::newFromText( $entry['pdbk'] );
  86                         }
  87                 }
  88                 unset( $nsLinks );
  89                 unset( $entry );
  90
  91                 foreach ( $this->interwikis as &$entry ) {
  92                         $entry['title'] = Title::newFromText( $entry['pdbk'] );
  93                 }
  94                 unset( $entry );
  95         }
  96
  97         /**
  98          * Merge another LinkHolderArray into this one
  99          * @param LinkHolderArray $other
 100          */
 101         public function merge( $other ) {
 102                 foreach ( $other->internals as $ns => $entries ) {
 103                         $this->size += count( $entries );
 104                         if ( !isset( $this->internals[$ns] ) ) {
 105                                 $this->internals[$ns] = $entries;
 106                         } else {
 107                                 $this->internals[$ns] += $entries;
 108                         }
 109                 }
 110                 $this->interwikis += $other->interwikis;
 111         }
 112
 113         /**
 114          * Merge a LinkHolderArray from another parser instance into this one. The
 115          * keys will not be preserved. Any text which went with the old
 116          * LinkHolderArray and needs to work with the new one should be passed in
 117          * the $texts array. The strings in this array will have their link holders
 118          * converted for use in the destination link holder. The resulting array of
 119          * strings will be returned.
 120          *
 121          * @param LinkHolderArray $other
 122          * @param array $texts Array of strings
 123          * @return array
 124          */
 125         public function mergeForeign( $other, $texts ) {
 126                 $this->tempIdOffset = $idOffset = $this->parent->nextLinkID();
 127                 $maxId = 0;
 128
 129                 # Renumber internal links
 130                 foreach ( $other->internals as $ns => $nsLinks ) {
 131                         foreach ( $nsLinks as $key => $entry ) {
 132                                 $newKey = $idOffset + $key;
 133                                 $this->internals[$ns][$newKey] = $entry;
 134                                 $maxId = $newKey > $maxId ? $newKey : $maxId;
 135                         }
 136                 }
 137                 $texts = preg_replace_callback( '/(<!--LINK \d+:)(\d+)(-->)/',
 138                         [ $this, 'mergeForeignCallback' ], $texts );
 139
 140                 # Renumber interwiki links
 141                 foreach ( $other->interwikis as $key => $entry ) {
 142                         $newKey = $idOffset + $key;
 143                         $this->interwikis[$newKey] = $entry;
 144                         $maxId = $newKey > $maxId ? $newKey : $maxId;
 145                 }
 146                 $texts = preg_replace_callback( '/(<!--IWLINK )(\d+)(-->)/',
 147                         [ $this, 'mergeForeignCallback' ], $texts );
 148
 149                 # Set the parent link ID to be beyond the highest used ID
 150                 $this->parent->setLinkID( $maxId + 1 );
 151                 $this->tempIdOffset = null;
 152                 return $texts;
 153         }
 154
 155         /**
 156          * @param array $m
 157          * @return string
 158          */
 159         protected function mergeForeignCallback( $m ) {
 160                 return $m[1] . ( $m[2] + $this->tempIdOffset ) . $m[3];
 161         }
 162
 163         /**
 164          * Get a subset of the current LinkHolderArray which is sufficient to
 165          * interpret the given text.
 166          * @param string $text
 167          * @return LinkHolderArray
 168          */
 169         public function getSubArray( $text ) {
 170                 $sub = new LinkHolderArray( $this->parent );
 171
 172                 # Internal links
 173                 $pos = 0;
 174                 while ( $pos < strlen( $text ) ) {
 175                         if ( !preg_match( '/<!--LINK (\d+):(\d+)-->/',
 176                                 $text, $m, PREG_OFFSET_CAPTURE, $pos )
 177                         ) {
 178                                 break;
 179                         }
 180                         $ns = $m[1][0];
 181                         $key = $m[2][0];
 182                         $sub->internals[$ns][$key] = $this->internals[$ns][$key];
 183                         $pos = $m[0][1] + strlen( $m[0][0] );
 184                 }
 185
 186                 # Interwiki links
 187                 $pos = 0;
 188                 while ( $pos < strlen( $text ) ) {
 189                         if ( !preg_match( '/<!--IWLINK (\d+)-->/', $text, $m, PREG_OFFSET_CAPTURE, $pos ) ) {
 190                                 break;
 191                         }
 192                         $key = $m[1][0];
 193                         $sub->interwikis[$key] = $this->interwikis[$key];
 194                         $pos = $m[0][1] + strlen( $m[0][0] );
 195                 }
 196                 return $sub;
 197         }
 198
 199         /**
 200          * Returns true if the memory requirements of this object are getting large
 201          * @return bool
 202          */
 203         public function isBig() {
 204                 global $wgLinkHolderBatchSize;
 205                 return $this->size > $wgLinkHolderBatchSize;
 206         }
 207
 208         /**
 209          * Clear all stored link holders.
 210          * Make sure you don't have any text left using these link holders, before you call this
 211          */
 212         public function clear() {
 213                 $this->internals = [];
 214                 $this->interwikis = [];
 215                 $this->size = 0;
 216         }
 217
 218         /**
 219          * Make a link placeholder. The text returned can be later resolved to a real link with
 220          * replaceLinkHolders(). This is done for two reasons: firstly to avoid further
 221          * parsing of interwiki links, and secondly to allow all existence checks and
 222          * article length checks (for stub links) to be bundled into a single query.
 223          *
 224          * @param Title $nt
 225          * @param string $text
 226          * @param array $query [optional]
 227          * @param string $trail [optional]
 228          * @param string $prefix [optional]
 229          * @return string
 230          */
 231         public function makeHolder( $nt, $text = '', $query = [], $trail = '', $prefix = '' ) {
 232                 if ( !is_object( $nt ) ) {
 233                         # Fail gracefully
 234                         $retVal = "<!-- ERROR -->{$prefix}{$text}{$trail}";
 235                 } else {
 236                         # Separate the link trail from the rest of the link
 237                         list( $inside, $trail ) = Linker::splitTrail( $trail );
 238
 239                         $entry = [
 240                                 'title' => $nt,
 241                                 'text' => $prefix . $text . $inside,
 242                                 'pdbk' => $nt->getPrefixedDBkey(),
 243                         ];
 244                         if ( $query !== [] ) {
 245                                 $entry['query'] = $query;
 246                         }
 247
 248                         if ( $nt->isExternal() ) {
 249                                 // Use a globally unique ID to keep the objects mergable
 250                                 $key = $this->parent->nextLinkID();
 251                                 $this->interwikis[$key] = $entry;
 252                                 $retVal = "<!--IWLINK $key-->{$trail}";
 253                         } else {
 254                                 $key = $this->parent->nextLinkID();
 255                                 $ns = $nt->getNamespace();
 256                                 $this->internals[$ns][$key] = $entry;
 257                                 $retVal = "<!--LINK $ns:$key-->{$trail}";
 258                         }
 259                         $this->size++;
 260                 }
 261                 return $retVal;
 262         }
 263
 264         /**
 265          * Replace <!--LINK--> link placeholders with actual links, in the buffer
 266          *
 267          * @param string $text
 268          */
 269         public function replace( &$text ) {
 270
 271                 $this->replaceInternal( $text );
 272                 $this->replaceInterwiki( $text );
 273
 274         }
 275
 276         /**
 277          * Replace internal links
 278          * @param string $text
 279          */
 280         protected function replaceInternal( &$text ) {
 281                 if ( !$this->internals ) {
 282                         return;
 283                 }
 284
 285                 global $wgContLang, $wgContentHandlerUseDB, $wgPageLanguageUseDB;
 286
 287                 $colours = [];
 288                 $linkCache = LinkCache::singleton();
 289                 $output = $this->parent->getOutput();
 290
 291                 $dbr = wfGetDB( DB_SLAVE );
 292                 $threshold = $this->parent->getOptions()->getStubThreshold();
 293
 294                 # Sort by namespace
 295                 ksort( $this->internals );
 296
 297                 $linkcolour_ids = [];
 298
 299                 # Generate query
 300                 $lb = new LinkBatch();
 301                 $lb->setCaller( __METHOD__ );
 302
 303                 foreach ( $this->internals as $ns => $entries ) {
 304                         foreach ( $entries as $entry ) {
 305                                 /** @var Title $title */
 306                                 $title = $entry['title'];
 307                                 $pdbk = $entry['pdbk'];
 308
 309                                 # Skip invalid entries.
 310                                 # Result will be ugly, but prevents crash.
 311                                 if ( is_null( $title ) ) {
 312                                         continue;
 313                                 }
 314
 315                                 # Check if it's a static known link, e.g. interwiki
 316                                 if ( $title->isAlwaysKnown() ) {
 317                                         $colours[$pdbk] = '';
 318                                 } elseif ( $ns == NS_SPECIAL ) {
 319                                         $colours[$pdbk] = 'new';
 320                                 } else {
 321                                         $id = $linkCache->getGoodLinkID( $pdbk );
 322                                         if ( $id != 0 ) {
 323                                                 $colours[$pdbk] = Linker::getLinkColour( $title, $threshold );
 324                                                 $output->addLink( $title, $id );
 325                                                 $linkcolour_ids[$id] = $pdbk;
 326                                         } elseif ( $linkCache->isBadLink( $pdbk ) ) {
 327                                                 $colours[$pdbk] = 'new';
 328                                         } else {
 329                                                 # Not in the link cache, add it to the query
 330                                                 $lb->addObj( $title );
 331                                         }
 332                                 }
 333                         }
 334                 }
 335                 if ( !$lb->isEmpty() ) {
 336                         $fields = [ 'page_id', 'page_namespace', 'page_title',
 337                                 'page_is_redirect', 'page_len', 'page_latest' ];
 338
 339                         if ( $wgContentHandlerUseDB ) {
 340                                 $fields[] = 'page_content_model';
 341                         }
 342                         if ( $wgPageLanguageUseDB ) {
 343                                 $fields[] = 'page_lang';
 344                         }
 345
 346                         $res = $dbr->select(
 347                                 'page',
 348                                 $fields,
 349                                 $lb->constructSet( 'page', $dbr ),
 350                                 __METHOD__
 351                         );
 352
 353                         # Fetch data and form into an associative array
 354                         # non-existent = broken
 355                         foreach ( $res as $s ) {
 356                                 $title = Title::makeTitle( $s->page_namespace, $s->page_title );
 357                                 $pdbk = $title->getPrefixedDBkey();
 358                                 $linkCache->addGoodLinkObjFromRow( $title, $s );
 359                                 $output->addLink( $title, $s->page_id );
 360                                 # @todo FIXME: Convoluted data flow
 361                                 # The redirect status and length is passed to getLinkColour via the LinkCache
 362                                 # Use formal parameters instead
 363                                 $colours[$pdbk] = Linker::getLinkColour( $title, $threshold );
 364                                 // add id to the extension todolist
 365                                 $linkcolour_ids[$s->page_id] = $pdbk;
 366                         }
 367                         unset( $res );
 368                 }
 369                 if ( count( $linkcolour_ids ) ) {
 370                         // pass an array of page_ids to an extension
 371                         Hooks::run( 'GetLinkColours', [ $linkcolour_ids, &$colours ] );
 372                 }
 373
 374                 # Do a second query for different language variants of links and categories
 375                 if ( $wgContLang->hasVariants() ) {
 376                         $this->doVariants( $colours );
 377                 }
 378
 379                 # Construct search and replace arrays
 380                 $replacePairs = [];
 381                 foreach ( $this->internals as $ns => $entries ) {
 382                         foreach ( $entries as $index => $entry ) {
 383                                 $pdbk = $entry['pdbk'];
 384                                 $title = $entry['title'];
 385                                 $query = isset( $entry['query'] ) ? $entry['query'] : [];
 386                                 $key = "$ns:$index";
 387                                 $searchkey = "<!--LINK $key-->";
 388                                 $displayText = $entry['text'];
 389                                 if ( isset( $entry['selflink'] ) ) {
 390                                         $replacePairs[$searchkey] = Linker::makeSelfLinkObj( $title, $displayText, $query );
 391                                         continue;
 392                                 }
 393                                 if ( $displayText === '' ) {
 394                                         $displayText = null;
 395                                 }
 396                                 if ( !isset( $colours[$pdbk] ) ) {
 397                                         $colours[$pdbk] = 'new';
 398                                 }
 399                                 $attribs = [];
 400                                 if ( $colours[$pdbk] == 'new' ) {
 401                                         $linkCache->addBadLinkObj( $title );
 402                                         $output->addLink( $title, 0 );
 403                                         $type = [ 'broken' ];
 404                                 } else {
 405                                         if ( $colours[$pdbk] != '' ) {
 406                                                 $attribs['class'] = $colours[$pdbk];
 407                                         }
 408                                         $type = [ 'known', 'noclasses' ];
 409                                 }
 410                                 $replacePairs[$searchkey] = Linker::link( $title, $displayText,
 411                                                 $attribs, $query, $type );
 412                         }
 413                 }
 414                 $replacer = new HashtableReplacer( $replacePairs, 1 );
 415
 416                 # Do the thing
 417                 $text = preg_replace_callback(
 418                         '/(<!--LINK .*?-->)/',
 419                         $replacer->cb(),
 420                         $text
 421                 );
 422
 423         }
 424
 425         /**
 426          * Replace interwiki links
 427          * @param string $text
 428          */
 429         protected function replaceInterwiki( &$text ) {
 430                 if ( empty( $this->interwikis ) ) {
 431                         return;
 432                 }
 433
 434                 # Make interwiki link HTML
 435                 $output = $this->parent->getOutput();
 436                 $replacePairs = [];
 437                 $options = [
 438                         'stubThreshold' => $this->parent->getOptions()->getStubThreshold(),
 439                 ];
 440                 foreach ( $this->interwikis as $key => $link ) {
 441                         $replacePairs[$key] = Linker::link( $link['title'], $link['text'], [], [], $options );
 442                         $output->addInterwikiLink( $link['title'] );
 443                 }
 444                 $replacer = new HashtableReplacer( $replacePairs, 1 );
 445
 446                 $text = preg_replace_callback(
 447                         '/<!--IWLINK (.*?)-->/',
 448                         $replacer->cb(),
 449                         $text );
 450         }
 451
 452         /**
 453          * Modify $this->internals and $colours according to language variant linking rules
 454          * @param array $colours
 455          */
 456         protected function doVariants( &$colours ) {
 457                 global $wgContLang, $wgContentHandlerUseDB, $wgPageLanguageUseDB;
 458                 $linkBatch = new LinkBatch();
 459                 $variantMap = []; // maps $pdbkey_Variant => $keys (of link holders)
 460                 $output = $this->parent->getOutput();
 461                 $linkCache = LinkCache::singleton();
 462                 $threshold = $this->parent->getOptions()->getStubThreshold();
 463                 $titlesToBeConverted = '';
 464                 $titlesAttrs = [];
 465
 466                 // Concatenate titles to a single string, thus we only need auto convert the
 467                 // single string to all variants. This would improve parser's performance
 468                 // significantly.
 469                 foreach ( $this->internals as $ns => $entries ) {
 470                         if ( $ns == NS_SPECIAL ) {
 471                                 continue;
 472                         }
 473                         foreach ( $entries as $index => $entry ) {
 474                                 $pdbk = $entry['pdbk'];
 475                                 // we only deal with new links (in its first query)
 476                                 if ( !isset( $colours[$pdbk] ) || $colours[$pdbk] === 'new' ) {
 477                                         $titlesAttrs[] = [ $index, $entry['title'] ];
 478                                         // separate titles with \0 because it would never appears
 479                                         // in a valid title
 480                                         $titlesToBeConverted .= $entry['title']->getText() . "\0";
 481                                 }
 482                         }
 483                 }
 484
 485                 // Now do the conversion and explode string to text of titles
 486                 $titlesAllVariants = $wgContLang->autoConvertToAllVariants( rtrim( $titlesToBeConverted, "\0" ) );
 487                 $allVariantsName = array_keys( $titlesAllVariants );
 488                 foreach ( $titlesAllVariants as &$titlesVariant ) {
 489                         $titlesVariant = explode( "\0", $titlesVariant );
 490                 }
 491
 492                 // Then add variants of links to link batch
 493                 $parentTitle = $this->parent->getTitle();
 494                 foreach ( $titlesAttrs as $i => $attrs ) {
 495                         /** @var Title $title */
 496                         list( $index, $title ) = $attrs;
 497                         $ns = $title->getNamespace();
 498                         $text = $title->getText();
 499
 500                         foreach ( $allVariantsName as $variantName ) {
 501                                 $textVariant = $titlesAllVariants[$variantName][$i];
 502                                 if ( $textVariant === $text ) {
 503                                         continue;
 504                                 }
 505
 506                                 $variantTitle = Title::makeTitle( $ns, $textVariant );
 507                                 if ( is_null( $variantTitle ) ) {
 508                                         continue;
 509                                 }
 510
 511                                 // Self-link checking for mixed/different variant titles. At this point, we
 512                                 // already know the exact title does not exist, so the link cannot be to a
 513                                 // variant of the current title that exists as a separate page.
 514                                 if ( $variantTitle->equals( $parentTitle ) && !$title->hasFragment() ) {
 515                                         $this->internals[$ns][$index]['selflink'] = true;
 516                                         continue 2;
 517                                 }
 518
 519                                 $linkBatch->addObj( $variantTitle );
 520                                 $variantMap[$variantTitle->getPrefixedDBkey()][] = "$ns:$index";
 521                         }
 522                 }
 523
 524                 // process categories, check if a category exists in some variant
 525                 $categoryMap = []; // maps $category_variant => $category (dbkeys)
 526                 $varCategories = []; // category replacements oldDBkey => newDBkey
 527                 foreach ( $output->getCategoryLinks() as $category ) {
 528                         $categoryTitle = Title::makeTitleSafe( NS_CATEGORY, $category );
 529                         $linkBatch->addObj( $categoryTitle );
 530                         $variants = $wgContLang->autoConvertToAllVariants( $category );
 531                         foreach ( $variants as $variant ) {
 532                                 if ( $variant !== $category ) {
 533                                         $variantTitle = Title::makeTitleSafe( NS_CATEGORY, $variant );
 534                                         if ( is_null( $variantTitle ) ) {
 535                                                 continue;
 536                                         }
 537                                         $linkBatch->addObj( $variantTitle );
 538                                         $categoryMap[$variant] = [ $category, $categoryTitle ];
 539                                 }
 540                         }
 541                 }
 542
 543                 if ( !$linkBatch->isEmpty() ) {
 544                         // construct query
 545                         $dbr = wfGetDB( DB_SLAVE );
 546                         $fields = [ 'page_id', 'page_namespace', 'page_title',
 547                                 'page_is_redirect', 'page_len', 'page_latest' ];
 548
 549                         if ( $wgContentHandlerUseDB ) {
 550                                 $fields[] = 'page_content_model';
 551                         }
 552                         if ( $wgPageLanguageUseDB ) {
 553                                 $fields[] = 'page_lang';
 554                         }
 555
 556                         $varRes = $dbr->select( 'page',
 557                                 $fields,
 558                                 $linkBatch->constructSet( 'page', $dbr ),
 559                                 __METHOD__
 560                         );
 561
 562                         $linkcolour_ids = [];
 563
 564                         // for each found variants, figure out link holders and replace
 565                         foreach ( $varRes as $s ) {
 566                                 $variantTitle = Title::makeTitle( $s->page_namespace, $s->page_title );
 567                                 $varPdbk = $variantTitle->getPrefixedDBkey();
 568                                 $vardbk = $variantTitle->getDBkey();
 569
 570                                 $holderKeys = [];
 571                                 if ( isset( $variantMap[$varPdbk] ) ) {
 572                                         $holderKeys = $variantMap[$varPdbk];
 573                                         $linkCache->addGoodLinkObjFromRow( $variantTitle, $s );
 574                                         $output->addLink( $variantTitle, $s->page_id );
 575                                 }
 576
 577                                 // loop over link holders
 578                                 foreach ( $holderKeys as $key ) {
 579                                         list( $ns, $index ) = explode( ':', $key, 2 );
 580                                         $entry =& $this->internals[$ns][$index];
 581                                         $pdbk = $entry['pdbk'];
 582
 583                                         if ( !isset( $colours[$pdbk] ) || $colours[$pdbk] === 'new' ) {
 584                                                 // found link in some of the variants, replace the link holder data
 585                                                 $entry['title'] = $variantTitle;
 586                                                 $entry['pdbk'] = $varPdbk;
 587
 588                                                 // set pdbk and colour
 589                                                 # @todo FIXME: Convoluted data flow
 590                                                 # The redirect status and length is passed to getLinkColour via the LinkCache
 591                                                 # Use formal parameters instead
 592                                                 $colours[$varPdbk] = Linker::getLinkColour( $variantTitle, $threshold );
 593                                                 $linkcolour_ids[$s->page_id] = $pdbk;
 594                                         }
 595                                 }
 596
 597                                 // check if the object is a variant of a category
 598                                 if ( isset( $categoryMap[$vardbk] ) ) {
 599                                         list( $oldkey, $oldtitle ) = $categoryMap[$vardbk];
 600                                         if ( !isset( $varCategories[$oldkey] ) && !$oldtitle->exists() ) {
 601                                                 $varCategories[$oldkey] = $vardbk;
 602                                         }
 603                                 }
 604                         }
 605                         Hooks::run( 'GetLinkColours', [ $linkcolour_ids, &$colours ] );
 606
 607                         // rebuild the categories in original order (if there are replacements)
 608                         if ( count( $varCategories ) > 0 ) {
 609                                 $newCats = [];
 610                                 $originalCats = $output->getCategories();
 611                                 foreach ( $originalCats as $cat => $sortkey ) {
 612                                         // make the replacement
 613                                         if ( array_key_exists( $cat, $varCategories ) ) {
 614                                                 $newCats[$varCategories[$cat]] = $sortkey;
 615                                         } else {
 616                                                 $newCats[$cat] = $sortkey;
 617                                         }
 618                                 }
 619                                 $output->setCategoryLinks( $newCats );
 620                         }
 621                 }
 622         }
 623
 624         /**
 625          * Replace <!--LINK--> link placeholders with plain text of links
 626          * (not HTML-formatted).
 627          *
 628          * @param string $text
 629          * @return string
 630          */
 631         public function replaceText( $text ) {
 632
 633                 $text = preg_replace_callback(
 634                         '/<!--(LINK|IWLINK) (.*?)-->/',
 635                         [ &$this, 'replaceTextCallback' ],
 636                         $text );
 637
 638                 return $text;
 639         }
 640
 641         /**
 642          * Callback for replaceText()
 643          *
 644          * @param array $matches
 645          * @return string
 646          * @private
 647          */
 648         public function replaceTextCallback( $matches ) {
 649                 $type = $matches[1];
 650                 $key = $matches[2];
 651                 if ( $type == 'LINK' ) {
 652                         list( $ns, $index ) = explode( ':', $key, 2 );
 653                         if ( isset( $this->internals[$ns][$index]['text'] ) ) {
 654                                 return $this->internals[$ns][$index]['text'];
 655                         }
 656                 } elseif ( $type == 'IWLINK' ) {
 657                         if ( isset( $this->interwikis[$key]['text'] ) ) {
 658                                 return $this->interwikis[$key]['text'];
 659                         }
 660                 }
 661                 return $matches[0];
 662         }
 663 }