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                 $this->replaceInternal( $text );
 271                 $this->replaceInterwiki( $text );
 272         }
 273
 274         /**
 275          * Replace internal links
 276          * @param string $text
 277          */
 278         protected function replaceInternal( &$text ) {
 279                 if ( !$this->internals ) {
 280                         return;
 281                 }
 282
 283                 global $wgContLang;
 284
 285                 $colours = [];
 286                 $linkCache = LinkCache::singleton();
 287                 $output = $this->parent->getOutput();
 288                 $linkRenderer = $this->parent->getLinkRenderer();
 289
 290                 $dbr = wfGetDB( DB_REPLICA );
 291
 292                 # Sort by namespace
 293                 ksort( $this->internals );
 294
 295                 $linkcolour_ids = [];
 296
 297                 # Generate query
 298                 $lb = new LinkBatch();
 299                 $lb->setCaller( __METHOD__ );
 300
 301                 foreach ( $this->internals as $ns => $entries ) {
 302                         foreach ( $entries as $entry ) {
 303                                 /** @var Title $title */
 304                                 $title = $entry['title'];
 305                                 $pdbk = $entry['pdbk'];
 306
 307                                 # Skip invalid entries.
 308                                 # Result will be ugly, but prevents crash.
 309                                 if ( is_null( $title ) ) {
 310                                         continue;
 311                                 }
 312
 313                                 # Check if it's a static known link, e.g. interwiki
 314                                 if ( $title->isAlwaysKnown() ) {
 315                                         $colours[$pdbk] = '';
 316                                 } elseif ( $ns == NS_SPECIAL ) {
 317                                         $colours[$pdbk] = 'new';
 318                                 } else {
 319                                         $id = $linkCache->getGoodLinkID( $pdbk );
 320                                         if ( $id != 0 ) {
 321                                                 $colours[$pdbk] = $linkRenderer->getLinkClasses( $title );
 322                                                 $output->addLink( $title, $id );
 323                                                 $linkcolour_ids[$id] = $pdbk;
 324                                         } elseif ( $linkCache->isBadLink( $pdbk ) ) {
 325                                                 $colours[$pdbk] = 'new';
 326                                         } else {
 327                                                 # Not in the link cache, add it to the query
 328                                                 $lb->addObj( $title );
 329                                         }
 330                                 }
 331                         }
 332                 }
 333                 if ( !$lb->isEmpty() ) {
 334                         $fields = array_merge(
 335                                 LinkCache::getSelectFields(),
 336                                 [ 'page_namespace', 'page_title' ]
 337                         );
 338
 339                         $res = $dbr->select(
 340                                 'page',
 341                                 $fields,
 342                                 $lb->constructSet( 'page', $dbr ),
 343                                 __METHOD__
 344                         );
 345
 346                         # Fetch data and form into an associative array
 347                         # non-existent = broken
 348                         foreach ( $res as $s ) {
 349                                 $title = Title::makeTitle( $s->page_namespace, $s->page_title );
 350                                 $pdbk = $title->getPrefixedDBkey();
 351                                 $linkCache->addGoodLinkObjFromRow( $title, $s );
 352                                 $output->addLink( $title, $s->page_id );
 353                                 $colours[$pdbk] = $linkRenderer->getLinkClasses( $title );
 354                                 // add id to the extension todolist
 355                                 $linkcolour_ids[$s->page_id] = $pdbk;
 356                         }
 357                         unset( $res );
 358                 }
 359                 if ( count( $linkcolour_ids ) ) {
 360                         // pass an array of page_ids to an extension
 361                         Hooks::run( 'GetLinkColours', [ $linkcolour_ids, &$colours ] );
 362                 }
 363
 364                 # Do a second query for different language variants of links and categories
 365                 if ( $wgContLang->hasVariants() ) {
 366                         $this->doVariants( $colours );
 367                 }
 368
 369                 # Construct search and replace arrays
 370                 $replacePairs = [];
 371                 foreach ( $this->internals as $ns => $entries ) {
 372                         foreach ( $entries as $index => $entry ) {
 373                                 $pdbk = $entry['pdbk'];
 374                                 $title = $entry['title'];
 375                                 $query = isset( $entry['query'] ) ? $entry['query'] : [];
 376                                 $key = "$ns:$index";
 377                                 $searchkey = "<!--LINK $key-->";
 378                                 $displayText = $entry['text'];
 379                                 if ( isset( $entry['selflink'] ) ) {
 380                                         $replacePairs[$searchkey] = Linker::makeSelfLinkObj( $title, $displayText, $query );
 381                                         continue;
 382                                 }
 383                                 if ( $displayText === '' ) {
 384                                         $displayText = null;
 385                                 } else {
 386                                         $displayText = new HtmlArmor( $displayText );
 387                                 }
 388                                 if ( !isset( $colours[$pdbk] ) ) {
 389                                         $colours[$pdbk] = 'new';
 390                                 }
 391                                 $attribs = [];
 392                                 if ( $colours[$pdbk] == 'new' ) {
 393                                         $linkCache->addBadLinkObj( $title );
 394                                         $output->addLink( $title, 0 );
 395                                         $link = $linkRenderer->makeBrokenLink(
 396                                                 $title, $displayText, $attribs, $query
 397                                         );
 398                                 } else {
 399                                         $link = $linkRenderer->makePreloadedLink(
 400                                                 $title, $displayText, $colours[$pdbk], $attribs, $query
 401                                         );
 402                                 }
 403
 404                                 $replacePairs[$searchkey] = $link;
 405                         }
 406                 }
 407                 $replacer = new HashtableReplacer( $replacePairs, 1 );
 408
 409                 # Do the thing
 410                 $text = preg_replace_callback(
 411                         '/(<!--LINK .*?-->)/',
 412                         $replacer->cb(),
 413                         $text
 414                 );
 415         }
 416
 417         /**
 418          * Replace interwiki links
 419          * @param string $text
 420          */
 421         protected function replaceInterwiki( &$text ) {
 422                 if ( empty( $this->interwikis ) ) {
 423                         return;
 424                 }
 425
 426                 # Make interwiki link HTML
 427                 $output = $this->parent->getOutput();
 428                 $replacePairs = [];
 429                 $linkRenderer = $this->parent->getLinkRenderer();
 430                 foreach ( $this->interwikis as $key => $link ) {
 431                         $replacePairs[$key] = $linkRenderer->makeLink(
 432                                 $link['title'],
 433                                 new HtmlArmor( $link['text'] )
 434                         );
 435                         $output->addInterwikiLink( $link['title'] );
 436                 }
 437                 $replacer = new HashtableReplacer( $replacePairs, 1 );
 438
 439                 $text = preg_replace_callback(
 440                         '/<!--IWLINK (.*?)-->/',
 441                         $replacer->cb(),
 442                         $text );
 443         }
 444
 445         /**
 446          * Modify $this->internals and $colours according to language variant linking rules
 447          * @param array $colours
 448          */
 449         protected function doVariants( &$colours ) {
 450                 global $wgContLang;
 451                 $linkBatch = new LinkBatch();
 452                 $variantMap = []; // maps $pdbkey_Variant => $keys (of link holders)
 453                 $output = $this->parent->getOutput();
 454                 $linkCache = LinkCache::singleton();
 455                 $titlesToBeConverted = '';
 456                 $titlesAttrs = [];
 457
 458                 // Concatenate titles to a single string, thus we only need auto convert the
 459                 // single string to all variants. This would improve parser's performance
 460                 // significantly.
 461                 foreach ( $this->internals as $ns => $entries ) {
 462                         if ( $ns == NS_SPECIAL ) {
 463                                 continue;
 464                         }
 465                         foreach ( $entries as $index => $entry ) {
 466                                 $pdbk = $entry['pdbk'];
 467                                 // we only deal with new links (in its first query)
 468                                 if ( !isset( $colours[$pdbk] ) || $colours[$pdbk] === 'new' ) {
 469                                         $titlesAttrs[] = [ $index, $entry['title'] ];
 470                                         // separate titles with \0 because it would never appears
 471                                         // in a valid title
 472                                         $titlesToBeConverted .= $entry['title']->getText() . "\0";
 473                                 }
 474                         }
 475                 }
 476
 477                 // Now do the conversion and explode string to text of titles
 478                 $titlesAllVariants = $wgContLang->autoConvertToAllVariants( rtrim( $titlesToBeConverted, "\0" ) );
 479                 $allVariantsName = array_keys( $titlesAllVariants );
 480                 foreach ( $titlesAllVariants as &$titlesVariant ) {
 481                         $titlesVariant = explode( "\0", $titlesVariant );
 482                 }
 483
 484                 // Then add variants of links to link batch
 485                 $parentTitle = $this->parent->getTitle();
 486                 foreach ( $titlesAttrs as $i => $attrs ) {
 487                         /** @var Title $title */
 488                         list( $index, $title ) = $attrs;
 489                         $ns = $title->getNamespace();
 490                         $text = $title->getText();
 491
 492                         foreach ( $allVariantsName as $variantName ) {
 493                                 $textVariant = $titlesAllVariants[$variantName][$i];
 494                                 if ( $textVariant === $text ) {
 495                                         continue;
 496                                 }
 497
 498                                 $variantTitle = Title::makeTitle( $ns, $textVariant );
 499
 500                                 // Self-link checking for mixed/different variant titles. At this point, we
 501                                 // already know the exact title does not exist, so the link cannot be to a
 502                                 // variant of the current title that exists as a separate page.
 503                                 if ( $variantTitle->equals( $parentTitle ) && !$title->hasFragment() ) {
 504                                         $this->internals[$ns][$index]['selflink'] = true;
 505                                         continue 2;
 506                                 }
 507
 508                                 $linkBatch->addObj( $variantTitle );
 509                                 $variantMap[$variantTitle->getPrefixedDBkey()][] = "$ns:$index";
 510                         }
 511                 }
 512
 513                 // process categories, check if a category exists in some variant
 514                 $categoryMap = []; // maps $category_variant => $category (dbkeys)
 515                 $varCategories = []; // category replacements oldDBkey => newDBkey
 516                 foreach ( $output->getCategoryLinks() as $category ) {
 517                         $categoryTitle = Title::makeTitleSafe( NS_CATEGORY, $category );
 518                         $linkBatch->addObj( $categoryTitle );
 519                         $variants = $wgContLang->autoConvertToAllVariants( $category );
 520                         foreach ( $variants as $variant ) {
 521                                 if ( $variant !== $category ) {
 522                                         $variantTitle = Title::makeTitleSafe( NS_CATEGORY, $variant );
 523                                         if ( is_null( $variantTitle ) ) {
 524                                                 continue;
 525                                         }
 526                                         $linkBatch->addObj( $variantTitle );
 527                                         $categoryMap[$variant] = [ $category, $categoryTitle ];
 528                                 }
 529                         }
 530                 }
 531
 532                 if ( !$linkBatch->isEmpty() ) {
 533                         // construct query
 534                         $dbr = wfGetDB( DB_REPLICA );
 535                         $fields = array_merge(
 536                                 LinkCache::getSelectFields(),
 537                                 [ 'page_namespace', 'page_title' ]
 538                         );
 539
 540                         $varRes = $dbr->select( 'page',
 541                                 $fields,
 542                                 $linkBatch->constructSet( 'page', $dbr ),
 543                                 __METHOD__
 544                         );
 545
 546                         $linkcolour_ids = [];
 547                         $linkRenderer = $this->parent->getLinkRenderer();
 548
 549                         // for each found variants, figure out link holders and replace
 550                         foreach ( $varRes as $s ) {
 551                                 $variantTitle = Title::makeTitle( $s->page_namespace, $s->page_title );
 552                                 $varPdbk = $variantTitle->getPrefixedDBkey();
 553                                 $vardbk = $variantTitle->getDBkey();
 554
 555                                 $holderKeys = [];
 556                                 if ( isset( $variantMap[$varPdbk] ) ) {
 557                                         $holderKeys = $variantMap[$varPdbk];
 558                                         $linkCache->addGoodLinkObjFromRow( $variantTitle, $s );
 559                                         $output->addLink( $variantTitle, $s->page_id );
 560                                 }
 561
 562                                 // loop over link holders
 563                                 foreach ( $holderKeys as $key ) {
 564                                         list( $ns, $index ) = explode( ':', $key, 2 );
 565                                         $entry =& $this->internals[$ns][$index];
 566                                         $pdbk = $entry['pdbk'];
 567
 568                                         if ( !isset( $colours[$pdbk] ) || $colours[$pdbk] === 'new' ) {
 569                                                 // found link in some of the variants, replace the link holder data
 570                                                 $entry['title'] = $variantTitle;
 571                                                 $entry['pdbk'] = $varPdbk;
 572
 573                                                 // set pdbk and colour
 574                                                 $colours[$varPdbk] = $linkRenderer->getLinkClasses( $variantTitle );
 575                                                 $linkcolour_ids[$s->page_id] = $pdbk;
 576                                         }
 577                                 }
 578
 579                                 // check if the object is a variant of a category
 580                                 if ( isset( $categoryMap[$vardbk] ) ) {
 581                                         list( $oldkey, $oldtitle ) = $categoryMap[$vardbk];
 582                                         if ( !isset( $varCategories[$oldkey] ) && !$oldtitle->exists() ) {
 583                                                 $varCategories[$oldkey] = $vardbk;
 584                                         }
 585                                 }
 586                         }
 587                         Hooks::run( 'GetLinkColours', [ $linkcolour_ids, &$colours ] );
 588
 589                         // rebuild the categories in original order (if there are replacements)
 590                         if ( count( $varCategories ) > 0 ) {
 591                                 $newCats = [];
 592                                 $originalCats = $output->getCategories();
 593                                 foreach ( $originalCats as $cat => $sortkey ) {
 594                                         // make the replacement
 595                                         if ( array_key_exists( $cat, $varCategories ) ) {
 596                                                 $newCats[$varCategories[$cat]] = $sortkey;
 597                                         } else {
 598                                                 $newCats[$cat] = $sortkey;
 599                                         }
 600                                 }
 601                                 $output->setCategoryLinks( $newCats );
 602                         }
 603                 }
 604         }
 605
 606         /**
 607          * Replace <!--LINK--> link placeholders with plain text of links
 608          * (not HTML-formatted).
 609          *
 610          * @param string $text
 611          * @return string
 612          */
 613         public function replaceText( $text ) {
 614                 $text = preg_replace_callback(
 615                         '/<!--(LINK|IWLINK) (.*?)-->/',
 616                         [ &$this, 'replaceTextCallback' ],
 617                         $text );
 618
 619                 return $text;
 620         }
 621
 622         /**
 623          * Callback for replaceText()
 624          *
 625          * @param array $matches
 626          * @return string
 627          * @private
 628          */
 629         public function replaceTextCallback( $matches ) {
 630                 $type = $matches[1];
 631                 $key = $matches[2];
 632                 if ( $type == 'LINK' ) {
 633                         list( $ns, $index ) = explode( ':', $key, 2 );
 634                         if ( isset( $this->internals[$ns][$index]['text'] ) ) {
 635                                 return $this->internals[$ns][$index]['text'];
 636                         }
 637                 } elseif ( $type == 'IWLINK' ) {
 638                         if ( isset( $this->interwikis[$key]['text'] ) ) {
 639                                 return $this->interwikis[$key]['text'];
 640                         }
 641                 }
 642                 return $matches[0];
 643         }
 644 }