includes/parser/Preprocessor_DOM.php

   1 <?php
   2 /**
   3  * Preprocessor using PHP's dom extension
   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 Preprocessor_DOM implements Preprocessor {
  28         /** @var Parser */
  29         public $parser;
  30
  31         protected $memoryLimit;
  32
  33         const CACHE_VERSION = 1;
  34
  35         function __construct( $parser ) {
  36                 $this->parser = $parser;
  37                 $mem = ini_get( 'memory_limit' );
  38                 $this->memoryLimit = false;
  39                 if ( strval( $mem ) !== '' && $mem != -1 ) {
  40                         if ( preg_match( '/^\d+$/', $mem ) ) {
  41                                 $this->memoryLimit = $mem;
  42                         } elseif ( preg_match( '/^(\d+)M$/i', $mem, $m ) ) {
  43                                 $this->memoryLimit = $m[1] * 1048576;
  44                         }
  45                 }
  46         }
  47
  48         /**
  49          * @return PPFrame_DOM
  50          */
  51         function newFrame() {
  52                 return new PPFrame_DOM( $this );
  53         }
  54
  55         /**
  56          * @param array $args
  57          * @return PPCustomFrame_DOM
  58          */
  59         function newCustomFrame( $args ) {
  60                 return new PPCustomFrame_DOM( $this, $args );
  61         }
  62
  63         /**
  64          * @param array $values
  65          * @return PPNode_DOM
  66          */
  67         function newPartNodeArray( $values ) {
  68                 //NOTE: DOM manipulation is slower than building & parsing XML! (or so Tim sais)
  69                 $xml = "<list>";
  70
  71                 foreach ( $values as $k => $val ) {
  72                         if ( is_int( $k ) ) {
  73                                 $xml .= "<part><name index=\"$k\"/><value>"
  74                                         . htmlspecialchars( $val ) . "</value></part>";
  75                         } else {
  76                                 $xml .= "<part><name>" . htmlspecialchars( $k )
  77                                         . "</name>=<value>" . htmlspecialchars( $val ) . "</value></part>";
  78                         }
  79                 }
  80
  81                 $xml .= "</list>";
  82
  83                 $dom = new DOMDocument();
  84                 $dom->loadXML( $xml );
  85                 $root = $dom->documentElement;
  86
  87                 $node = new PPNode_DOM( $root->childNodes );
  88                 return $node;
  89         }
  90
  91         /**
  92          * @throws MWException
  93          * @return bool
  94          */
  95         function memCheck() {
  96                 if ( $this->memoryLimit === false ) {
  97                         return true;
  98                 }
  99                 $usage = memory_get_usage();
 100                 if ( $usage > $this->memoryLimit * 0.9 ) {
 101                         $limit = intval( $this->memoryLimit * 0.9 / 1048576 + 0.5 );
 102                         throw new MWException( "Preprocessor hit 90% memory limit ($limit MB)" );
 103                 }
 104                 return $usage <= $this->memoryLimit * 0.8;
 105         }
 106
 107         /**
 108          * Preprocess some wikitext and return the document tree.
 109          * This is the ghost of Parser::replace_variables().
 110          *
 111          * @param string $text The text to parse
 112          * @param int $flags Bitwise combination of:
 113          *     Parser::PTD_FOR_INCLUSION  Handle "<noinclude>" and "<includeonly>"
 114          *                                as if the text is being included. Default
 115          *                                is to assume a direct page view.
 116          *
 117          * The generated DOM tree must depend only on the input text and the flags.
 118          * The DOM tree must be the same in OT_HTML and OT_WIKI mode, to avoid a regression of bug 4899.
 119          *
 120          * Any flag added to the $flags parameter here, or any other parameter liable to cause a
 121          * change in the DOM tree for a given text, must be passed through the section identifier
 122          * in the section edit link and thus back to extractSections().
 123          *
 124          * The output of this function is currently only cached in process memory, but a persistent
 125          * cache may be implemented at a later date which takes further advantage of these strict
 126          * dependency requirements.
 127          *
 128          * @throws MWException
 129          * @return PPNode_DOM
 130          */
 131         function preprocessToObj( $text, $flags = 0 ) {
 132                 wfProfileIn( __METHOD__ );
 133                 global $wgMemc, $wgPreprocessorCacheThreshold;
 134
 135                 $xml = false;
 136                 $cacheable = ( $wgPreprocessorCacheThreshold !== false
 137                         && strlen( $text ) > $wgPreprocessorCacheThreshold );
 138                 if ( $cacheable ) {
 139                         wfProfileIn( __METHOD__ . '-cacheable' );
 140
 141                         $cacheKey = wfMemcKey( 'preprocess-xml', md5( $text ), $flags );
 142                         $cacheValue = $wgMemc->get( $cacheKey );
 143                         if ( $cacheValue ) {
 144                                 $version = substr( $cacheValue, 0, 8 );
 145                                 if ( intval( $version ) == self::CACHE_VERSION ) {
 146                                         $xml = substr( $cacheValue, 8 );
 147                                         // From the cache
 148                                         wfDebugLog( "Preprocessor", "Loaded preprocessor XML from memcached (key $cacheKey)" );
 149                                 }
 150                         }
 151                         if ( $xml === false ) {
 152                                 wfProfileIn( __METHOD__ . '-cache-miss' );
 153                                 $xml = $this->preprocessToXml( $text, $flags );
 154                                 $cacheValue = sprintf( "%08d", self::CACHE_VERSION ) . $xml;
 155                                 $wgMemc->set( $cacheKey, $cacheValue, 86400 );
 156                                 wfProfileOut( __METHOD__ . '-cache-miss' );
 157                                 wfDebugLog( "Preprocessor", "Saved preprocessor XML to memcached (key $cacheKey)" );
 158                         }
 159                 } else {
 160                         $xml = $this->preprocessToXml( $text, $flags );
 161                 }
 162
 163                 // Fail if the number of elements exceeds acceptable limits
 164                 // Do not attempt to generate the DOM
 165                 $this->parser->mGeneratedPPNodeCount += substr_count( $xml, '<' );
 166                 $max = $this->parser->mOptions->getMaxGeneratedPPNodeCount();
 167                 if ( $this->parser->mGeneratedPPNodeCount > $max ) {
 168                         if ( $cacheable ) {
 169                                 wfProfileOut( __METHOD__ . '-cacheable' );
 170                         }
 171                         wfProfileOut( __METHOD__ );
 172                         throw new MWException( __METHOD__ . ': generated node count limit exceeded' );
 173                 }
 174
 175                 wfProfileIn( __METHOD__ . '-loadXML' );
 176                 $dom = new DOMDocument;
 177                 wfSuppressWarnings();
 178                 $result = $dom->loadXML( $xml );
 179                 wfRestoreWarnings();
 180                 if ( !$result ) {
 181                         // Try running the XML through UtfNormal to get rid of invalid characters
 182                         $xml = UtfNormal::cleanUp( $xml );
 183                         // 1 << 19 == XML_PARSE_HUGE, needed so newer versions of libxml2
 184                         // don't barf when the XML is >256 levels deep.
 185                         $result = $dom->loadXML( $xml, 1 << 19 );
 186                 }
 187                 if ( $result ) {
 188                         $obj = new PPNode_DOM( $dom->documentElement );
 189                 }
 190                 wfProfileOut( __METHOD__ . '-loadXML' );
 191
 192                 if ( $cacheable ) {
 193                         wfProfileOut( __METHOD__ . '-cacheable' );
 194                 }
 195
 196                 wfProfileOut( __METHOD__ );
 197
 198                 if ( !$result ) {
 199                         throw new MWException( __METHOD__ . ' generated invalid XML' );
 200                 }
 201                 return $obj;
 202         }
 203
 204         /**
 205          * @param string $text
 206          * @param int $flags
 207          * @return string
 208          */
 209         function preprocessToXml( $text, $flags = 0 ) {
 210                 wfProfileIn( __METHOD__ );
 211                 $rules = array(
 212                         '{' => array(
 213                                 'end' => '}',
 214                                 'names' => array(
 215                                         2 => 'template',
 216                                         3 => 'tplarg',
 217                                 ),
 218                                 'min' => 2,
 219                                 'max' => 3,
 220                         ),
 221                         '[' => array(
 222                                 'end' => ']',
 223                                 'names' => array( 2 => null ),
 224                                 'min' => 2,
 225                                 'max' => 2,
 226                         )
 227                 );
 228
 229                 $forInclusion = $flags & Parser::PTD_FOR_INCLUSION;
 230
 231                 $xmlishElements = $this->parser->getStripList();
 232                 $enableOnlyinclude = false;
 233                 if ( $forInclusion ) {
 234                         $ignoredTags = array( 'includeonly', '/includeonly' );
 235                         $ignoredElements = array( 'noinclude' );
 236                         $xmlishElements[] = 'noinclude';
 237                         if ( strpos( $text, '<onlyinclude>' ) !== false
 238                                 && strpos( $text, '</onlyinclude>' ) !== false
 239                         ) {
 240                                 $enableOnlyinclude = true;
 241                         }
 242                 } else {
 243                         $ignoredTags = array( 'noinclude', '/noinclude', 'onlyinclude', '/onlyinclude' );
 244                         $ignoredElements = array( 'includeonly' );
 245                         $xmlishElements[] = 'includeonly';
 246                 }
 247                 $xmlishRegex = implode( '|', array_merge( $xmlishElements, $ignoredTags ) );
 248
 249                 // Use "A" modifier (anchored) instead of "^", because ^ doesn't work with an offset
 250                 $elementsRegex = "~($xmlishRegex)(?:\s|\/>|>)|(!--)~iA";
 251
 252                 $stack = new PPDStack;
 253
 254                 $searchBase = "[{<\n"; #}
 255                 // For fast reverse searches
 256                 $revText = strrev( $text );
 257                 $lengthText = strlen( $text );
 258
 259                 // Input pointer, starts out pointing to a pseudo-newline before the start
 260                 $i = 0;
 261                 // Current accumulator
 262                 $accum =& $stack->getAccum();
 263                 $accum = '<root>';
 264                 // True to find equals signs in arguments
 265                 $findEquals = false;
 266                 // True to take notice of pipe characters
 267                 $findPipe = false;
 268                 $headingIndex = 1;
 269                 // True if $i is inside a possible heading
 270                 $inHeading = false;
 271                 // True if there are no more greater-than (>) signs right of $i
 272                 $noMoreGT = false;
 273                 // True to ignore all input up to the next <onlyinclude>
 274                 $findOnlyinclude = $enableOnlyinclude;
 275                 // Do a line-start run without outputting an LF character
 276                 $fakeLineStart = true;
 277
 278                 while ( true ) {
 279                         //$this->memCheck();
 280
 281                         if ( $findOnlyinclude ) {
 282                                 // Ignore all input up to the next <onlyinclude>
 283                                 $startPos = strpos( $text, '<onlyinclude>', $i );
 284                                 if ( $startPos === false ) {
 285                                         // Ignored section runs to the end
 286                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i ) ) . '</ignore>';
 287                                         break;
 288                                 }
 289                                 $tagEndPos = $startPos + strlen( '<onlyinclude>' ); // past-the-end
 290                                 $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i, $tagEndPos - $i ) ) . '</ignore>';
 291                                 $i = $tagEndPos;
 292                                 $findOnlyinclude = false;
 293                         }
 294
 295                         if ( $fakeLineStart ) {
 296                                 $found = 'line-start';
 297                                 $curChar = '';
 298                         } else {
 299                                 # Find next opening brace, closing brace or pipe
 300                                 $search = $searchBase;
 301                                 if ( $stack->top === false ) {
 302                                         $currentClosing = '';
 303                                 } else {
 304                                         $currentClosing = $stack->top->close;
 305                                         $search .= $currentClosing;
 306                                 }
 307                                 if ( $findPipe ) {
 308                                         $search .= '|';
 309                                 }
 310                                 if ( $findEquals ) {
 311                                         // First equals will be for the template
 312                                         $search .= '=';
 313                                 }
 314                                 $rule = null;
 315                                 # Output literal section, advance input counter
 316                                 $literalLength = strcspn( $text, $search, $i );
 317                                 if ( $literalLength > 0 ) {
 318                                         $accum .= htmlspecialchars( substr( $text, $i, $literalLength ) );
 319                                         $i += $literalLength;
 320                                 }
 321                                 if ( $i >= $lengthText ) {
 322                                         if ( $currentClosing == "\n" ) {
 323                                                 // Do a past-the-end run to finish off the heading
 324                                                 $curChar = '';
 325                                                 $found = 'line-end';
 326                                         } else {
 327                                                 # All done
 328                                                 break;
 329                                         }
 330                                 } else {
 331                                         $curChar = $text[$i];
 332                                         if ( $curChar == '|' ) {
 333                                                 $found = 'pipe';
 334                                         } elseif ( $curChar == '=' ) {
 335                                                 $found = 'equals';
 336                                         } elseif ( $curChar == '<' ) {
 337                                                 $found = 'angle';
 338                                         } elseif ( $curChar == "\n" ) {
 339                                                 if ( $inHeading ) {
 340                                                         $found = 'line-end';
 341                                                 } else {
 342                                                         $found = 'line-start';
 343                                                 }
 344                                         } elseif ( $curChar == $currentClosing ) {
 345                                                 $found = 'close';
 346                                         } elseif ( isset( $rules[$curChar] ) ) {
 347                                                 $found = 'open';
 348                                                 $rule = $rules[$curChar];
 349                                         } else {
 350                                                 # Some versions of PHP have a strcspn which stops on null characters
 351                                                 # Ignore and continue
 352                                                 ++$i;
 353                                                 continue;
 354                                         }
 355                                 }
 356                         }
 357
 358                         if ( $found == 'angle' ) {
 359                                 $matches = false;
 360                                 // Handle </onlyinclude>
 361                                 if ( $enableOnlyinclude
 362                                         && substr( $text, $i, strlen( '</onlyinclude>' ) ) == '</onlyinclude>'
 363                                 ) {
 364                                         $findOnlyinclude = true;
 365                                         continue;
 366                                 }
 367
 368                                 // Determine element name
 369                                 if ( !preg_match( $elementsRegex, $text, $matches, 0, $i + 1 ) ) {
 370                                         // Element name missing or not listed
 371                                         $accum .= '&lt;';
 372                                         ++$i;
 373                                         continue;
 374                                 }
 375                                 // Handle comments
 376                                 if ( isset( $matches[2] ) && $matches[2] == '!--' ) {
 377
 378                                         // To avoid leaving blank lines, when a sequence of
 379                                         // space-separated comments is both preceded and followed by
 380                                         // a newline (ignoring spaces), then
 381                                         // trim leading and trailing spaces and the trailing newline.
 382
 383                                         // Find the end
 384                                         $endPos = strpos( $text, '-->', $i + 4 );
 385                                         if ( $endPos === false ) {
 386                                                 // Unclosed comment in input, runs to end
 387                                                 $inner = substr( $text, $i );
 388                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 389                                                 $i = $lengthText;
 390                                         } else {
 391                                                 // Search backwards for leading whitespace
 392                                                 $wsStart = $i ? ( $i - strspn( $revText, " \t", $lengthText - $i ) ) : 0;
 393
 394                                                 // Search forwards for trailing whitespace
 395                                                 // $wsEnd will be the position of the last space (or the '>' if there's none)
 396                                                 $wsEnd = $endPos + 2 + strspn( $text, " \t", $endPos + 3 );
 397
 398                                                 // Keep looking forward as long as we're finding more
 399                                                 // comments.
 400                                                 $comments = array( array( $wsStart, $wsEnd ) );
 401                                                 while ( substr( $text, $wsEnd + 1, 4 ) == '<!--' ) {
 402                                                         $c = strpos( $text, '-->', $wsEnd + 4 );
 403                                                         if ( $c === false ) {
 404                                                                 break;
 405                                                         }
 406                                                         $c = $c + 2 + strspn( $text, " \t", $c + 3 );
 407                                                         $comments[] = array( $wsEnd + 1, $c );
 408                                                         $wsEnd = $c;
 409                                                 }
 410
 411                                                 // Eat the line if possible
 412                                                 // TODO: This could theoretically be done if $wsStart == 0, i.e. for comments at
 413                                                 // the overall start. That's not how Sanitizer::removeHTMLcomments() did it, but
 414                                                 // it's a possible beneficial b/c break.
 415                                                 if ( $wsStart > 0 && substr( $text, $wsStart - 1, 1 ) == "\n"
 416                                                         && substr( $text, $wsEnd + 1, 1 ) == "\n"
 417                                                 ) {
 418                                                         // Remove leading whitespace from the end of the accumulator
 419                                                         // Sanity check first though
 420                                                         $wsLength = $i - $wsStart;
 421                                                         if ( $wsLength > 0
 422                                                                 && strspn( $accum, " \t", -$wsLength ) === $wsLength
 423                                                         ) {
 424                                                                 $accum = substr( $accum, 0, -$wsLength );
 425                                                         }
 426
 427                                                         // Dump all but the last comment to the accumulator
 428                                                         foreach ( $comments as $j => $com ) {
 429                                                                 $startPos = $com[0];
 430                                                                 $endPos = $com[1] + 1;
 431                                                                 if ( $j == ( count( $comments ) - 1 ) ) {
 432                                                                         break;
 433                                                                 }
 434                                                                 $inner = substr( $text, $startPos, $endPos - $startPos );
 435                                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 436                                                         }
 437
 438                                                         // Do a line-start run next time to look for headings after the comment
 439                                                         $fakeLineStart = true;
 440                                                 } else {
 441                                                         // No line to eat, just take the comment itself
 442                                                         $startPos = $i;
 443                                                         $endPos += 2;
 444                                                 }
 445
 446                                                 if ( $stack->top ) {
 447                                                         $part = $stack->top->getCurrentPart();
 448                                                         if ( !( isset( $part->commentEnd ) && $part->commentEnd == $wsStart - 1 ) ) {
 449                                                                 $part->visualEnd = $wsStart;
 450                                                         }
 451                                                         // Else comments abutting, no change in visual end
 452                                                         $part->commentEnd = $endPos;
 453                                                 }
 454                                                 $i = $endPos + 1;
 455                                                 $inner = substr( $text, $startPos, $endPos - $startPos + 1 );
 456                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 457                                         }
 458                                         continue;
 459                                 }
 460                                 $name = $matches[1];
 461                                 $lowerName = strtolower( $name );
 462                                 $attrStart = $i + strlen( $name ) + 1;
 463
 464                                 // Find end of tag
 465                                 $tagEndPos = $noMoreGT ? false : strpos( $text, '>', $attrStart );
 466                                 if ( $tagEndPos === false ) {
 467                                         // Infinite backtrack
 468                                         // Disable tag search to prevent worst-case O(N^2) performance
 469                                         $noMoreGT = true;
 470                                         $accum .= '&lt;';
 471                                         ++$i;
 472                                         continue;
 473                                 }
 474
 475                                 // Handle ignored tags
 476                                 if ( in_array( $lowerName, $ignoredTags ) ) {
 477                                         $accum .= '<ignore>'
 478                                                 . htmlspecialchars( substr( $text, $i, $tagEndPos - $i + 1 ) )
 479                                                 . '</ignore>';
 480                                         $i = $tagEndPos + 1;
 481                                         continue;
 482                                 }
 483
 484                                 $tagStartPos = $i;
 485                                 if ( $text[$tagEndPos - 1] == '/' ) {
 486                                         $attrEnd = $tagEndPos - 1;
 487                                         $inner = null;
 488                                         $i = $tagEndPos + 1;
 489                                         $close = '';
 490                                 } else {
 491                                         $attrEnd = $tagEndPos;
 492                                         // Find closing tag
 493                                         if ( preg_match( "/<\/" . preg_quote( $name, '/' ) . "\s*>/i",
 494                                                         $text, $matches, PREG_OFFSET_CAPTURE, $tagEndPos + 1 )
 495                                         ) {
 496                                                 $inner = substr( $text, $tagEndPos + 1, $matches[0][1] - $tagEndPos - 1 );
 497                                                 $i = $matches[0][1] + strlen( $matches[0][0] );
 498                                                 $close = '<close>' . htmlspecialchars( $matches[0][0] ) . '</close>';
 499                                         } else {
 500                                                 // No end tag -- let it run out to the end of the text.
 501                                                 $inner = substr( $text, $tagEndPos + 1 );
 502                                                 $i = $lengthText;
 503                                                 $close = '';
 504                                         }
 505                                 }
 506                                 // <includeonly> and <noinclude> just become <ignore> tags
 507                                 if ( in_array( $lowerName, $ignoredElements ) ) {
 508                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $tagStartPos, $i - $tagStartPos ) )
 509                                                 . '</ignore>';
 510                                         continue;
 511                                 }
 512
 513                                 $accum .= '<ext>';
 514                                 if ( $attrEnd <= $attrStart ) {
 515                                         $attr = '';
 516                                 } else {
 517                                         $attr = substr( $text, $attrStart, $attrEnd - $attrStart );
 518                                 }
 519                                 $accum .= '<name>' . htmlspecialchars( $name ) . '</name>' .
 520                                         // Note that the attr element contains the whitespace between name and attribute,
 521                                         // this is necessary for precise reconstruction during pre-save transform.
 522                                         '<attr>' . htmlspecialchars( $attr ) . '</attr>';
 523                                 if ( $inner !== null ) {
 524                                         $accum .= '<inner>' . htmlspecialchars( $inner ) . '</inner>';
 525                                 }
 526                                 $accum .= $close . '</ext>';
 527                         } elseif ( $found == 'line-start' ) {
 528                                 // Is this the start of a heading?
 529                                 // Line break belongs before the heading element in any case
 530                                 if ( $fakeLineStart ) {
 531                                         $fakeLineStart = false;
 532                                 } else {
 533                                         $accum .= $curChar;
 534                                         $i++;
 535                                 }
 536
 537                                 $count = strspn( $text, '=', $i, 6 );
 538                                 if ( $count == 1 && $findEquals ) {
 539                                         // DWIM: This looks kind of like a name/value separator.
 540                                         // Let's let the equals handler have it and break the
 541                                         // potential heading. This is heuristic, but AFAICT the
 542                                         // methods for completely correct disambiguation are very
 543                                         // complex.
 544                                 } elseif ( $count > 0 ) {
 545                                         $piece = array(
 546                                                 'open' => "\n",
 547                                                 'close' => "\n",
 548                                                 'parts' => array( new PPDPart( str_repeat( '=', $count ) ) ),
 549                                                 'startPos' => $i,
 550                                                 'count' => $count );
 551                                         $stack->push( $piece );
 552                                         $accum =& $stack->getAccum();
 553                                         $flags = $stack->getFlags();
 554                                         extract( $flags );
 555                                         $i += $count;
 556                                 }
 557                         } elseif ( $found == 'line-end' ) {
 558                                 $piece = $stack->top;
 559                                 // A heading must be open, otherwise \n wouldn't have been in the search list
 560                                 assert( '$piece->open == "\n"' );
 561                                 $part = $piece->getCurrentPart();
 562                                 // Search back through the input to see if it has a proper close.
 563                                 // Do this using the reversed string since the other solutions
 564                                 // (end anchor, etc.) are inefficient.
 565                                 $wsLength = strspn( $revText, " \t", $lengthText - $i );
 566                                 $searchStart = $i - $wsLength;
 567                                 if ( isset( $part->commentEnd ) && $searchStart - 1 == $part->commentEnd ) {
 568                                         // Comment found at line end
 569                                         // Search for equals signs before the comment
 570                                         $searchStart = $part->visualEnd;
 571                                         $searchStart -= strspn( $revText, " \t", $lengthText - $searchStart );
 572                                 }
 573                                 $count = $piece->count;
 574                                 $equalsLength = strspn( $revText, '=', $lengthText - $searchStart );
 575                                 if ( $equalsLength > 0 ) {
 576                                         if ( $searchStart - $equalsLength == $piece->startPos ) {
 577                                                 // This is just a single string of equals signs on its own line
 578                                                 // Replicate the doHeadings behavior /={count}(.+)={count}/
 579                                                 // First find out how many equals signs there really are (don't stop at 6)
 580                                                 $count = $equalsLength;
 581                                                 if ( $count < 3 ) {
 582                                                         $count = 0;
 583                                                 } else {
 584                                                         $count = min( 6, intval( ( $count - 1 ) / 2 ) );
 585                                                 }
 586                                         } else {
 587                                                 $count = min( $equalsLength, $count );
 588                                         }
 589                                         if ( $count > 0 ) {
 590                                                 // Normal match, output <h>
 591                                                 $element = "<h level=\"$count\" i=\"$headingIndex\">$accum</h>";
 592                                                 $headingIndex++;
 593                                         } else {
 594                                                 // Single equals sign on its own line, count=0
 595                                                 $element = $accum;
 596                                         }
 597                                 } else {
 598                                         // No match, no <h>, just pass down the inner text
 599                                         $element = $accum;
 600                                 }
 601                                 // Unwind the stack
 602                                 $stack->pop();
 603                                 $accum =& $stack->getAccum();
 604                                 $flags = $stack->getFlags();
 605                                 extract( $flags );
 606
 607                                 // Append the result to the enclosing accumulator
 608                                 $accum .= $element;
 609                                 // Note that we do NOT increment the input pointer.
 610                                 // This is because the closing linebreak could be the opening linebreak of
 611                                 // another heading. Infinite loops are avoided because the next iteration MUST
 612                                 // hit the heading open case above, which unconditionally increments the
 613                                 // input pointer.
 614                         } elseif ( $found == 'open' ) {
 615                                 # count opening brace characters
 616                                 $count = strspn( $text, $curChar, $i );
 617
 618                                 # we need to add to stack only if opening brace count is enough for one of the rules
 619                                 if ( $count >= $rule['min'] ) {
 620                                         # Add it to the stack
 621                                         $piece = array(
 622                                                 'open' => $curChar,
 623                                                 'close' => $rule['end'],
 624                                                 'count' => $count,
 625                                                 'lineStart' => ( $i > 0 && $text[$i - 1] == "\n" ),
 626                                         );
 627
 628                                         $stack->push( $piece );
 629                                         $accum =& $stack->getAccum();
 630                                         $flags = $stack->getFlags();
 631                                         extract( $flags );
 632                                 } else {
 633                                         # Add literal brace(s)
 634                                         $accum .= htmlspecialchars( str_repeat( $curChar, $count ) );
 635                                 }
 636                                 $i += $count;
 637                         } elseif ( $found == 'close' ) {
 638                                 $piece = $stack->top;
 639                                 # lets check if there are enough characters for closing brace
 640                                 $maxCount = $piece->count;
 641                                 $count = strspn( $text, $curChar, $i, $maxCount );
 642
 643                                 # check for maximum matching characters (if there are 5 closing
 644                                 # characters, we will probably need only 3 - depending on the rules)
 645                                 $rule = $rules[$piece->open];
 646                                 if ( $count > $rule['max'] ) {
 647                                         # The specified maximum exists in the callback array, unless the caller
 648                                         # has made an error
 649                                         $matchingCount = $rule['max'];
 650                                 } else {
 651                                         # Count is less than the maximum
 652                                         # Skip any gaps in the callback array to find the true largest match
 653                                         # Need to use array_key_exists not isset because the callback can be null
 654                                         $matchingCount = $count;
 655                                         while ( $matchingCount > 0 && !array_key_exists( $matchingCount, $rule['names'] ) ) {
 656                                                 --$matchingCount;
 657                                         }
 658                                 }
 659
 660                                 if ( $matchingCount <= 0 ) {
 661                                         # No matching element found in callback array
 662                                         # Output a literal closing brace and continue
 663                                         $accum .= htmlspecialchars( str_repeat( $curChar, $count ) );
 664                                         $i += $count;
 665                                         continue;
 666                                 }
 667                                 $name = $rule['names'][$matchingCount];
 668                                 if ( $name === null ) {
 669                                         // No element, just literal text
 670                                         $element = $piece->breakSyntax( $matchingCount ) . str_repeat( $rule['end'], $matchingCount );
 671                                 } else {
 672                                         # Create XML element
 673                                         # Note: $parts is already XML, does not need to be encoded further
 674                                         $parts = $piece->parts;
 675                                         $title = $parts[0]->out;
 676                                         unset( $parts[0] );
 677
 678                                         # The invocation is at the start of the line if lineStart is set in
 679                                         # the stack, and all opening brackets are used up.
 680                                         if ( $maxCount == $matchingCount && !empty( $piece->lineStart ) ) {
 681                                                 $attr = ' lineStart="1"';
 682                                         } else {
 683                                                 $attr = '';
 684                                         }
 685
 686                                         $element = "<$name$attr>";
 687                                         $element .= "<title>$title</title>";
 688                                         $argIndex = 1;
 689                                         foreach ( $parts as $part ) {
 690                                                 if ( isset( $part->eqpos ) ) {
 691                                                         $argName = substr( $part->out, 0, $part->eqpos );
 692                                                         $argValue = substr( $part->out, $part->eqpos + 1 );
 693                                                         $element .= "<part><name>$argName</name>=<value>$argValue</value></part>";
 694                                                 } else {
 695                                                         $element .= "<part><name index=\"$argIndex\" /><value>{$part->out}</value></part>";
 696                                                         $argIndex++;
 697                                                 }
 698                                         }
 699                                         $element .= "</$name>";
 700                                 }
 701
 702                                 # Advance input pointer
 703                                 $i += $matchingCount;
 704
 705                                 # Unwind the stack
 706                                 $stack->pop();
 707                                 $accum =& $stack->getAccum();
 708
 709                                 # Re-add the old stack element if it still has unmatched opening characters remaining
 710                                 if ( $matchingCount < $piece->count ) {
 711                                         $piece->parts = array( new PPDPart );
 712                                         $piece->count -= $matchingCount;
 713                                         # do we still qualify for any callback with remaining count?
 714                                         $min = $rules[$piece->open]['min'];
 715                                         if ( $piece->count >= $min ) {
 716                                                 $stack->push( $piece );
 717                                                 $accum =& $stack->getAccum();
 718                                         } else {
 719                                                 $accum .= str_repeat( $piece->open, $piece->count );
 720                                         }
 721                                 }
 722                                 $flags = $stack->getFlags();
 723                                 extract( $flags );
 724
 725                                 # Add XML element to the enclosing accumulator
 726                                 $accum .= $element;
 727                         } elseif ( $found == 'pipe' ) {
 728                                 $findEquals = true; // shortcut for getFlags()
 729                                 $stack->addPart();
 730                                 $accum =& $stack->getAccum();
 731                                 ++$i;
 732                         } elseif ( $found == 'equals' ) {
 733                                 $findEquals = false; // shortcut for getFlags()
 734                                 $stack->getCurrentPart()->eqpos = strlen( $accum );
 735                                 $accum .= '=';
 736                                 ++$i;
 737                         }
 738                 }
 739
 740                 # Output any remaining unclosed brackets
 741                 foreach ( $stack->stack as $piece ) {
 742                         $stack->rootAccum .= $piece->breakSyntax();
 743                 }
 744                 $stack->rootAccum .= '</root>';
 745                 $xml = $stack->rootAccum;
 746
 747                 wfProfileOut( __METHOD__ );
 748
 749                 return $xml;
 750         }
 751 }
 752
 753 /**
 754  * Stack class to help Preprocessor::preprocessToObj()
 755  * @ingroup Parser
 756  */
 757 class PPDStack {
 758         /** @var array */
 759         public $stack;
 760
 761         /** @var string */
 762         public $rootAccum;
 763
 764         /** @var bool|PPDStack */
 765         public $top;
 766
 767         /** @var */
 768         public $out;
 769
 770         /** @var string */
 771         protected $elementClass = 'PPDStackElement';
 772
 773         protected static $false = false;
 774
 775         function __construct() {
 776                 $this->stack = array();
 777                 $this->top = false;
 778                 $this->rootAccum = '';
 779                 $this->accum =& $this->rootAccum;
 780         }
 781
 782         /**
 783          * @return int
 784          */
 785         function count() {
 786                 return count( $this->stack );
 787         }
 788
 789         function &getAccum() {
 790                 return $this->accum;
 791         }
 792
 793         function getCurrentPart() {
 794                 if ( $this->top === false ) {
 795                         return false;
 796                 } else {
 797                         return $this->top->getCurrentPart();
 798                 }
 799         }
 800
 801         function push( $data ) {
 802                 if ( $data instanceof $this->elementClass ) {
 803                         $this->stack[] = $data;
 804                 } else {
 805                         $class = $this->elementClass;
 806                         $this->stack[] = new $class( $data );
 807                 }
 808                 $this->top = $this->stack[count( $this->stack ) - 1];
 809                 $this->accum =& $this->top->getAccum();
 810         }
 811
 812         function pop() {
 813                 if ( !count( $this->stack ) ) {
 814                         throw new MWException( __METHOD__ . ': no elements remaining' );
 815                 }
 816                 $temp = array_pop( $this->stack );
 817
 818                 if ( count( $this->stack ) ) {
 819                         $this->top = $this->stack[count( $this->stack ) - 1];
 820                         $this->accum =& $this->top->getAccum();
 821                 } else {
 822                         $this->top = self::$false;
 823                         $this->accum =& $this->rootAccum;
 824                 }
 825                 return $temp;
 826         }
 827
 828         function addPart( $s = '' ) {
 829                 $this->top->addPart( $s );
 830                 $this->accum =& $this->top->getAccum();
 831         }
 832
 833         /**
 834          * @return array
 835          */
 836         function getFlags() {
 837                 if ( !count( $this->stack ) ) {
 838                         return array(
 839                                 'findEquals' => false,
 840                                 'findPipe' => false,
 841                                 'inHeading' => false,
 842                         );
 843                 } else {
 844                         return $this->top->getFlags();
 845                 }
 846         }
 847 }
 848
 849 /**
 850  * @ingroup Parser
 851  */
 852 class PPDStackElement {
 853         /** @var string Opening character (\n for heading) */
 854         public $open;
 855
 856         /** @var string Matching closing character */
 857         public $close;
 858
 859         /** @var int Number of opening characters found (number of "=" for heading) */
 860         public $count;
 861
 862         /** @var array PPDPart objects describing pipe-separated parts. */
 863         public $parts;
 864
 865         /**
 866          * @var bool True if the open char appeared at the start of the input line.
 867          * Not set for headings.
 868          */
 869         public $lineStart;
 870
 871         /** @var string */
 872         protected $partClass = 'PPDPart';
 873
 874         function __construct( $data = array() ) {
 875                 $class = $this->partClass;
 876                 $this->parts = array( new $class );
 877
 878                 foreach ( $data as $name => $value ) {
 879                         $this->$name = $value;
 880                 }
 881         }
 882
 883         function &getAccum() {
 884                 return $this->parts[count( $this->parts ) - 1]->out;
 885         }
 886
 887         function addPart( $s = '' ) {
 888                 $class = $this->partClass;
 889                 $this->parts[] = new $class( $s );
 890         }
 891
 892         function getCurrentPart() {
 893                 return $this->parts[count( $this->parts ) - 1];
 894         }
 895
 896         /**
 897          * @return array
 898          */
 899         function getFlags() {
 900                 $partCount = count( $this->parts );
 901                 $findPipe = $this->open != "\n" && $this->open != '[';
 902                 return array(
 903                         'findPipe' => $findPipe,
 904                         'findEquals' => $findPipe && $partCount > 1 && !isset( $this->parts[$partCount - 1]->eqpos ),
 905                         'inHeading' => $this->open == "\n",
 906                 );
 907         }
 908
 909         /**
 910          * Get the output string that would result if the close is not found.
 911          *
 912          * @return string
 913          */
 914         function breakSyntax( $openingCount = false ) {
 915                 if ( $this->open == "\n" ) {
 916                         $s = $this->parts[0]->out;
 917                 } else {
 918                         if ( $openingCount === false ) {
 919                                 $openingCount = $this->count;
 920                         }
 921                         $s = str_repeat( $this->open, $openingCount );
 922                         $first = true;
 923                         foreach ( $this->parts as $part ) {
 924                                 if ( $first ) {
 925                                         $first = false;
 926                                 } else {
 927                                         $s .= '|';
 928                                 }
 929                                 $s .= $part->out;
 930                         }
 931                 }
 932                 return $s;
 933         }
 934 }
 935
 936 /**
 937  * @ingroup Parser
 938  */
 939 class PPDPart {
 940         /** @var string */
 941         public $out;
 942
 943         // Optional member variables:
 944         //   eqpos        Position of equals sign in output accumulator
 945         //   commentEnd   Past-the-end input pointer for the last comment encountered
 946         //   visualEnd    Past-the-end input pointer for the end of the accumulator minus comments
 947
 948         function __construct( $out = '' ) {
 949                 $this->out = $out;
 950         }
 951 }
 952
 953 /**
 954  * An expansion frame, used as a context to expand the result of preprocessToObj()
 955  * @ingroup Parser
 956  */
 957 class PPFrame_DOM implements PPFrame {
 958         /** @var array */
 959         public $titleCache;
 960
 961         /**
 962          * @var array Hashtable listing templates which are disallowed for expansion
 963          *   in this frame, having been encountered previously in parent frames.
 964          */
 965         public $loopCheckHash;
 966
 967         /**
 968          * @var int Recursion depth of this frame, top = 0.
 969          * Note that this is NOT the same as expansion depth in expand()
 970          */
 971         public $depth;
 972
 973         /** @var Preprocessor */
 974         protected $preprocessor;
 975
 976         /** @var Parser */
 977         protected $parser;
 978
 979         /** @var Title */
 980         protected $title;
 981
 982         /**
 983          * Construct a new preprocessor frame.
 984          * @param Preprocessor $preprocessor The parent preprocessor
 985          */
 986         function __construct( $preprocessor ) {
 987                 $this->preprocessor = $preprocessor;
 988                 $this->parser = $preprocessor->parser;
 989                 $this->title = $this->parser->mTitle;
 990                 $this->titleCache = array( $this->title ? $this->title->getPrefixedDBkey() : false );
 991                 $this->loopCheckHash = array();
 992                 $this->depth = 0;
 993         }
 994
 995         /**
 996          * Create a new child frame
 997          * $args is optionally a multi-root PPNode or array containing the template arguments
 998          *
 999          * @param bool|array $args
1000          * @param Title|bool $title
1001          * @param int $indexOffset
1002          * @return PPTemplateFrame_DOM
1003          */
1004         function newChild( $args = false, $title = false, $indexOffset = 0 ) {
1005                 $namedArgs = array();
1006                 $numberedArgs = array();
1007                 if ( $title === false ) {
1008                         $title = $this->title;
1009                 }
1010                 if ( $args !== false ) {
1011                         $xpath = false;
1012                         if ( $args instanceof PPNode ) {
1013                                 $args = $args->node;
1014                         }
1015                         foreach ( $args as $arg ) {
1016                                 if ( $arg instanceof PPNode ) {
1017                                         $arg = $arg->node;
1018                                 }
1019                                 if ( !$xpath ) {
1020                                         $xpath = new DOMXPath( $arg->ownerDocument );
1021                                 }
1022
1023                                 $nameNodes = $xpath->query( 'name', $arg );
1024                                 $value = $xpath->query( 'value', $arg );
1025                                 if ( $nameNodes->item( 0 )->hasAttributes() ) {
1026                                         // Numbered parameter
1027                                         $index = $nameNodes->item( 0 )->attributes->getNamedItem( 'index' )->textContent;
1028                                         $index = $index - $indexOffset;
1029                                         $numberedArgs[$index] = $value->item( 0 );
1030                                         unset( $namedArgs[$index] );
1031                                 } else {
1032                                         // Named parameter
1033                                         $name = trim( $this->expand( $nameNodes->item( 0 ), PPFrame::STRIP_COMMENTS ) );
1034                                         $namedArgs[$name] = $value->item( 0 );
1035                                         unset( $numberedArgs[$name] );
1036                                 }
1037                         }
1038                 }
1039                 return new PPTemplateFrame_DOM( $this->preprocessor, $this, $numberedArgs, $namedArgs, $title );
1040         }
1041
1042         /**
1043          * @throws MWException
1044          * @param string|PPNode_DOM|DOMDocument $root
1045          * @param int $flags
1046          * @return string
1047          */
1048         function expand( $root, $flags = 0 ) {
1049                 static $expansionDepth = 0;
1050                 if ( is_string( $root ) ) {
1051                         return $root;
1052                 }
1053
1054                 if ( ++$this->parser->mPPNodeCount > $this->parser->mOptions->getMaxPPNodeCount() ) {
1055                         $this->parser->limitationWarn( 'node-count-exceeded',
1056                                 $this->parser->mPPNodeCount,
1057                                 $this->parser->mOptions->getMaxPPNodeCount()
1058                         );
1059                         return '<span class="error">Node-count limit exceeded</span>';
1060                 }
1061
1062                 if ( $expansionDepth > $this->parser->mOptions->getMaxPPExpandDepth() ) {
1063                         $this->parser->limitationWarn( 'expansion-depth-exceeded',
1064                                 $expansionDepth,
1065                                 $this->parser->mOptions->getMaxPPExpandDepth()
1066                         );
1067                         return '<span class="error">Expansion depth limit exceeded</span>';
1068                 }
1069                 wfProfileIn( __METHOD__ );
1070                 ++$expansionDepth;
1071                 if ( $expansionDepth > $this->parser->mHighestExpansionDepth ) {
1072                         $this->parser->mHighestExpansionDepth = $expansionDepth;
1073                 }
1074
1075                 if ( $root instanceof PPNode_DOM ) {
1076                         $root = $root->node;
1077                 }
1078                 if ( $root instanceof DOMDocument ) {
1079                         $root = $root->documentElement;
1080                 }
1081
1082                 $outStack = array( '', '' );
1083                 $iteratorStack = array( false, $root );
1084                 $indexStack = array( 0, 0 );
1085
1086                 while ( count( $iteratorStack ) > 1 ) {
1087                         $level = count( $outStack ) - 1;
1088                         $iteratorNode =& $iteratorStack[$level];
1089                         $out =& $outStack[$level];
1090                         $index =& $indexStack[$level];
1091
1092                         if ( $iteratorNode instanceof PPNode_DOM ) {
1093                                 $iteratorNode = $iteratorNode->node;
1094                         }
1095
1096                         if ( is_array( $iteratorNode ) ) {
1097                                 if ( $index >= count( $iteratorNode ) ) {
1098                                         // All done with this iterator
1099                                         $iteratorStack[$level] = false;
1100                                         $contextNode = false;
1101                                 } else {
1102                                         $contextNode = $iteratorNode[$index];
1103                                         $index++;
1104                                 }
1105                         } elseif ( $iteratorNode instanceof DOMNodeList ) {
1106                                 if ( $index >= $iteratorNode->length ) {
1107                                         // All done with this iterator
1108                                         $iteratorStack[$level] = false;
1109                                         $contextNode = false;
1110                                 } else {
1111                                         $contextNode = $iteratorNode->item( $index );
1112                                         $index++;
1113                                 }
1114                         } else {
1115                                 // Copy to $contextNode and then delete from iterator stack,
1116                                 // because this is not an iterator but we do have to execute it once
1117                                 $contextNode = $iteratorStack[$level];
1118                                 $iteratorStack[$level] = false;
1119                         }
1120
1121                         if ( $contextNode instanceof PPNode_DOM ) {
1122                                 $contextNode = $contextNode->node;
1123                         }
1124
1125                         $newIterator = false;
1126
1127                         if ( $contextNode === false ) {
1128                                 // nothing to do
1129                         } elseif ( is_string( $contextNode ) ) {
1130                                 $out .= $contextNode;
1131                         } elseif ( is_array( $contextNode ) || $contextNode instanceof DOMNodeList ) {
1132                                 $newIterator = $contextNode;
1133                         } elseif ( $contextNode instanceof DOMNode ) {
1134                                 if ( $contextNode->nodeType == XML_TEXT_NODE ) {
1135                                         $out .= $contextNode->nodeValue;
1136                                 } elseif ( $contextNode->nodeName == 'template' ) {
1137                                         # Double-brace expansion
1138                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1139                                         $titles = $xpath->query( 'title', $contextNode );
1140                                         $title = $titles->item( 0 );
1141                                         $parts = $xpath->query( 'part', $contextNode );
1142                                         if ( $flags & PPFrame::NO_TEMPLATES ) {
1143                                                 $newIterator = $this->virtualBracketedImplode( '{{', '|', '}}', $title, $parts );
1144                                         } else {
1145                                                 $lineStart = $contextNode->getAttribute( 'lineStart' );
1146                                                 $params = array(
1147                                                         'title' => new PPNode_DOM( $title ),
1148                                                         'parts' => new PPNode_DOM( $parts ),
1149                                                         'lineStart' => $lineStart );
1150                                                 $ret = $this->parser->braceSubstitution( $params, $this );
1151                                                 if ( isset( $ret['object'] ) ) {
1152                                                         $newIterator = $ret['object'];
1153                                                 } else {
1154                                                         $out .= $ret['text'];
1155                                                 }
1156                                         }
1157                                 } elseif ( $contextNode->nodeName == 'tplarg' ) {
1158                                         # Triple-brace expansion
1159                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1160                                         $titles = $xpath->query( 'title', $contextNode );
1161                                         $title = $titles->item( 0 );
1162                                         $parts = $xpath->query( 'part', $contextNode );
1163                                         if ( $flags & PPFrame::NO_ARGS ) {
1164                                                 $newIterator = $this->virtualBracketedImplode( '{{{', '|', '}}}', $title, $parts );
1165                                         } else {
1166                                                 $params = array(
1167                                                         'title' => new PPNode_DOM( $title ),
1168                                                         'parts' => new PPNode_DOM( $parts ) );
1169                                                 $ret = $this->parser->argSubstitution( $params, $this );
1170                                                 if ( isset( $ret['object'] ) ) {
1171                                                         $newIterator = $ret['object'];
1172                                                 } else {
1173                                                         $out .= $ret['text'];
1174                                                 }
1175                                         }
1176                                 } elseif ( $contextNode->nodeName == 'comment' ) {
1177                                         # HTML-style comment
1178                                         # Remove it in HTML, pre+remove and STRIP_COMMENTS modes
1179                                         if ( $this->parser->ot['html']
1180                                                 || ( $this->parser->ot['pre'] && $this->parser->mOptions->getRemoveComments() )
1181                                                 || ( $flags & PPFrame::STRIP_COMMENTS )
1182                                         ) {
1183                                                 $out .= '';
1184                                         } elseif ( $this->parser->ot['wiki'] && !( $flags & PPFrame::RECOVER_COMMENTS ) ) {
1185                                                 # Add a strip marker in PST mode so that pstPass2() can
1186                                                 # run some old-fashioned regexes on the result.
1187                                                 # Not in RECOVER_COMMENTS mode (extractSections) though.
1188                                                 $out .= $this->parser->insertStripItem( $contextNode->textContent );
1189                                         } else {
1190                                                 # Recover the literal comment in RECOVER_COMMENTS and pre+no-remove
1191                                                 $out .= $contextNode->textContent;
1192                                         }
1193                                 } elseif ( $contextNode->nodeName == 'ignore' ) {
1194                                         # Output suppression used by <includeonly> etc.
1195                                         # OT_WIKI will only respect <ignore> in substed templates.
1196                                         # The other output types respect it unless NO_IGNORE is set.
1197                                         # extractSections() sets NO_IGNORE and so never respects it.
1198                                         if ( ( !isset( $this->parent ) && $this->parser->ot['wiki'] )
1199                                                 || ( $flags & PPFrame::NO_IGNORE )
1200                                         ) {
1201                                                 $out .= $contextNode->textContent;
1202                                         } else {
1203                                                 $out .= '';
1204                                         }
1205                                 } elseif ( $contextNode->nodeName == 'ext' ) {
1206                                         # Extension tag
1207                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1208                                         $names = $xpath->query( 'name', $contextNode );
1209                                         $attrs = $xpath->query( 'attr', $contextNode );
1210                                         $inners = $xpath->query( 'inner', $contextNode );
1211                                         $closes = $xpath->query( 'close', $contextNode );
1212                                         $params = array(
1213                                                 'name' => new PPNode_DOM( $names->item( 0 ) ),
1214                                                 'attr' => $attrs->length > 0 ? new PPNode_DOM( $attrs->item( 0 ) ) : null,
1215                                                 'inner' => $inners->length > 0 ? new PPNode_DOM( $inners->item( 0 ) ) : null,
1216                                                 'close' => $closes->length > 0 ? new PPNode_DOM( $closes->item( 0 ) ) : null,
1217                                         );
1218                                         $out .= $this->parser->extensionSubstitution( $params, $this );
1219                                 } elseif ( $contextNode->nodeName == 'h' ) {
1220                                         # Heading
1221                                         $s = $this->expand( $contextNode->childNodes, $flags );
1222
1223                                         # Insert a heading marker only for <h> children of <root>
1224                                         # This is to stop extractSections from going over multiple tree levels
1225                                         if ( $contextNode->parentNode->nodeName == 'root' && $this->parser->ot['html'] ) {
1226                                                 # Insert heading index marker
1227                                                 $headingIndex = $contextNode->getAttribute( 'i' );
1228                                                 $titleText = $this->title->getPrefixedDBkey();
1229                                                 $this->parser->mHeadings[] = array( $titleText, $headingIndex );
1230                                                 $serial = count( $this->parser->mHeadings ) - 1;
1231                                                 $marker = "{$this->parser->mUniqPrefix}-h-$serial-" . Parser::MARKER_SUFFIX;
1232                                                 $count = $contextNode->getAttribute( 'level' );
1233                                                 $s = substr( $s, 0, $count ) . $marker . substr( $s, $count );
1234                                                 $this->parser->mStripState->addGeneral( $marker, '' );
1235                                         }
1236                                         $out .= $s;
1237                                 } else {
1238                                         # Generic recursive expansion
1239                                         $newIterator = $contextNode->childNodes;
1240                                 }
1241                         } else {
1242                                 wfProfileOut( __METHOD__ );
1243                                 throw new MWException( __METHOD__ . ': Invalid parameter type' );
1244                         }
1245
1246                         if ( $newIterator !== false ) {
1247                                 if ( $newIterator instanceof PPNode_DOM ) {
1248                                         $newIterator = $newIterator->node;
1249                                 }
1250                                 $outStack[] = '';
1251                                 $iteratorStack[] = $newIterator;
1252                                 $indexStack[] = 0;
1253                         } elseif ( $iteratorStack[$level] === false ) {
1254                                 // Return accumulated value to parent
1255                                 // With tail recursion
1256                                 while ( $iteratorStack[$level] === false && $level > 0 ) {
1257                                         $outStack[$level - 1] .= $out;
1258                                         array_pop( $outStack );
1259                                         array_pop( $iteratorStack );
1260                                         array_pop( $indexStack );
1261                                         $level--;
1262                                 }
1263                         }
1264                 }
1265                 --$expansionDepth;
1266                 wfProfileOut( __METHOD__ );
1267                 return $outStack[0];
1268         }
1269
1270         /**
1271          * @param string $sep
1272          * @param int $flags
1273          * @return string
1274          */
1275         function implodeWithFlags( $sep, $flags /*, ... */ ) {
1276                 $args = array_slice( func_get_args(), 2 );
1277
1278                 $first = true;
1279                 $s = '';
1280                 foreach ( $args as $root ) {
1281                         if ( $root instanceof PPNode_DOM ) {
1282                                 $root = $root->node;
1283                         }
1284                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1285                                 $root = array( $root );
1286                         }
1287                         foreach ( $root as $node ) {
1288                                 if ( $first ) {
1289                                         $first = false;
1290                                 } else {
1291                                         $s .= $sep;
1292                                 }
1293                                 $s .= $this->expand( $node, $flags );
1294                         }
1295                 }
1296                 return $s;
1297         }
1298
1299         /**
1300          * Implode with no flags specified
1301          * This previously called implodeWithFlags but has now been inlined to reduce stack depth
1302          *
1303          * @param string $sep
1304          * @return string
1305          */
1306         function implode( $sep /*, ... */ ) {
1307                 $args = array_slice( func_get_args(), 1 );
1308
1309                 $first = true;
1310                 $s = '';
1311                 foreach ( $args as $root ) {
1312                         if ( $root instanceof PPNode_DOM ) {
1313                                 $root = $root->node;
1314                         }
1315                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1316                                 $root = array( $root );
1317                         }
1318                         foreach ( $root as $node ) {
1319                                 if ( $first ) {
1320                                         $first = false;
1321                                 } else {
1322                                         $s .= $sep;
1323                                 }
1324                                 $s .= $this->expand( $node );
1325                         }
1326                 }
1327                 return $s;
1328         }
1329
1330         /**
1331          * Makes an object that, when expand()ed, will be the same as one obtained
1332          * with implode()
1333          *
1334          * @param string $sep
1335          * @return array
1336          */
1337         function virtualImplode( $sep /*, ... */ ) {
1338                 $args = array_slice( func_get_args(), 1 );
1339                 $out = array();
1340                 $first = true;
1341
1342                 foreach ( $args as $root ) {
1343                         if ( $root instanceof PPNode_DOM ) {
1344                                 $root = $root->node;
1345                         }
1346                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1347                                 $root = array( $root );
1348                         }
1349                         foreach ( $root as $node ) {
1350                                 if ( $first ) {
1351                                         $first = false;
1352                                 } else {
1353                                         $out[] = $sep;
1354                                 }
1355                                 $out[] = $node;
1356                         }
1357                 }
1358                 return $out;
1359         }
1360
1361         /**
1362          * Virtual implode with brackets
1363          * @param string $start
1364          * @param string $sep
1365          * @param string $end
1366          * @return array
1367          */
1368         function virtualBracketedImplode( $start, $sep, $end /*, ... */ ) {
1369                 $args = array_slice( func_get_args(), 3 );
1370                 $out = array( $start );
1371                 $first = true;
1372
1373                 foreach ( $args as $root ) {
1374                         if ( $root instanceof PPNode_DOM ) {
1375                                 $root = $root->node;
1376                         }
1377                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1378                                 $root = array( $root );
1379                         }
1380                         foreach ( $root as $node ) {
1381                                 if ( $first ) {
1382                                         $first = false;
1383                                 } else {
1384                                         $out[] = $sep;
1385                                 }
1386                                 $out[] = $node;
1387                         }
1388                 }
1389                 $out[] = $end;
1390                 return $out;
1391         }
1392
1393         function __toString() {
1394                 return 'frame{}';
1395         }
1396
1397         function getPDBK( $level = false ) {
1398                 if ( $level === false ) {
1399                         return $this->title->getPrefixedDBkey();
1400                 } else {
1401                         return isset( $this->titleCache[$level] ) ? $this->titleCache[$level] : false;
1402                 }
1403         }
1404
1405         /**
1406          * @return array
1407          */
1408         function getArguments() {
1409                 return array();
1410         }
1411
1412         /**
1413          * @return array
1414          */
1415         function getNumberedArguments() {
1416                 return array();
1417         }
1418
1419         /**
1420          * @return array
1421          */
1422         function getNamedArguments() {
1423                 return array();
1424         }
1425
1426         /**
1427          * Returns true if there are no arguments in this frame
1428          *
1429          * @return bool
1430          */
1431         function isEmpty() {
1432                 return true;
1433         }
1434
1435         function getArgument( $name ) {
1436                 return false;
1437         }
1438
1439         /**
1440          * Returns true if the infinite loop check is OK, false if a loop is detected
1441          *
1442          * @param Title $title
1443          * @return bool
1444          */
1445         function loopCheck( $title ) {
1446                 return !isset( $this->loopCheckHash[$title->getPrefixedDBkey()] );
1447         }
1448
1449         /**
1450          * Return true if the frame is a template frame
1451          *
1452          * @return bool
1453          */
1454         function isTemplate() {
1455                 return false;
1456         }
1457
1458         /**
1459          * Get a title of frame
1460          *
1461          * @return Title
1462          */
1463         function getTitle() {
1464                 return $this->title;
1465         }
1466 }
1467
1468 /**
1469  * Expansion frame with template arguments
1470  * @ingroup Parser
1471  */
1472 class PPTemplateFrame_DOM extends PPFrame_DOM {
1473         /** @var PPFrame_DOM */
1474         public $parent;
1475
1476         /** @var array */
1477         protected $numberedArgs;
1478
1479         /** @var array */
1480         protected $namedArgs;
1481
1482         /** @var array */
1483         protected $numberedExpansionCache;
1484
1485         /** @var string[] */
1486         protected $namedExpansionCache;
1487
1488         /**
1489          * @param Preprocessor $preprocessor
1490          * @param PPFrame_DOM $parent
1491          * @param array $numberedArgs
1492          * @param array $namedArgs
1493          * @param Title $title
1494          */
1495         function __construct( $preprocessor, $parent = false, $numberedArgs = array(),
1496                 $namedArgs = array(), $title = false
1497         ) {
1498                 parent::__construct( $preprocessor );
1499
1500                 $this->parent = $parent;
1501                 $this->numberedArgs = $numberedArgs;
1502                 $this->namedArgs = $namedArgs;
1503                 $this->title = $title;
1504                 $pdbk = $title ? $title->getPrefixedDBkey() : false;
1505                 $this->titleCache = $parent->titleCache;
1506                 $this->titleCache[] = $pdbk;
1507                 $this->loopCheckHash = /*clone*/ $parent->loopCheckHash;
1508                 if ( $pdbk !== false ) {
1509                         $this->loopCheckHash[$pdbk] = true;
1510                 }
1511                 $this->depth = $parent->depth + 1;
1512                 $this->numberedExpansionCache = $this->namedExpansionCache = array();
1513         }
1514
1515         function __toString() {
1516                 $s = 'tplframe{';
1517                 $first = true;
1518                 $args = $this->numberedArgs + $this->namedArgs;
1519                 foreach ( $args as $name => $value ) {
1520                         if ( $first ) {
1521                                 $first = false;
1522                         } else {
1523                                 $s .= ', ';
1524                         }
1525                         $s .= "\"$name\":\"" .
1526                                 str_replace( '"', '\\"', $value->ownerDocument->saveXML( $value ) ) . '"';
1527                 }
1528                 $s .= '}';
1529                 return $s;
1530         }
1531
1532         /**
1533          * Returns true if there are no arguments in this frame
1534          *
1535          * @return bool
1536          */
1537         function isEmpty() {
1538                 return !count( $this->numberedArgs ) && !count( $this->namedArgs );
1539         }
1540
1541         function getArguments() {
1542                 $arguments = array();
1543                 foreach ( array_merge(
1544                                 array_keys( $this->numberedArgs ),
1545                                 array_keys( $this->namedArgs ) ) as $key ) {
1546                         $arguments[$key] = $this->getArgument( $key );
1547                 }
1548                 return $arguments;
1549         }
1550
1551         function getNumberedArguments() {
1552                 $arguments = array();
1553                 foreach ( array_keys( $this->numberedArgs ) as $key ) {
1554                         $arguments[$key] = $this->getArgument( $key );
1555                 }
1556                 return $arguments;
1557         }
1558
1559         function getNamedArguments() {
1560                 $arguments = array();
1561                 foreach ( array_keys( $this->namedArgs ) as $key ) {
1562                         $arguments[$key] = $this->getArgument( $key );
1563                 }
1564                 return $arguments;
1565         }
1566
1567         function getNumberedArgument( $index ) {
1568                 if ( !isset( $this->numberedArgs[$index] ) ) {
1569                         return false;
1570                 }
1571                 if ( !isset( $this->numberedExpansionCache[$index] ) ) {
1572                         # No trimming for unnamed arguments
1573                         $this->numberedExpansionCache[$index] = $this->parent->expand(
1574                                 $this->numberedArgs[$index],
1575                                 PPFrame::STRIP_COMMENTS
1576                         );
1577                 }
1578                 return $this->numberedExpansionCache[$index];
1579         }
1580
1581         function getNamedArgument( $name ) {
1582                 if ( !isset( $this->namedArgs[$name] ) ) {
1583                         return false;
1584                 }
1585                 if ( !isset( $this->namedExpansionCache[$name] ) ) {
1586                         # Trim named arguments post-expand, for backwards compatibility
1587                         $this->namedExpansionCache[$name] = trim(
1588                                 $this->parent->expand( $this->namedArgs[$name], PPFrame::STRIP_COMMENTS ) );
1589                 }
1590                 return $this->namedExpansionCache[$name];
1591         }
1592
1593         function getArgument( $name ) {
1594                 $text = $this->getNumberedArgument( $name );
1595                 if ( $text === false ) {
1596                         $text = $this->getNamedArgument( $name );
1597                 }
1598                 return $text;
1599         }
1600
1601         /**
1602          * Return true if the frame is a template frame
1603          *
1604          * @return bool
1605          */
1606         function isTemplate() {
1607                 return true;
1608         }
1609 }
1610
1611 /**
1612  * Expansion frame with custom arguments
1613  * @ingroup Parser
1614  */
1615 class PPCustomFrame_DOM extends PPFrame_DOM {
1616         protected $args;
1617
1618         function __construct( $preprocessor, $args ) {
1619                 parent::__construct( $preprocessor );
1620                 $this->args = $args;
1621         }
1622
1623         function __toString() {
1624                 $s = 'cstmframe{';
1625                 $first = true;
1626                 foreach ( $this->args as $name => $value ) {
1627                         if ( $first ) {
1628                                 $first = false;
1629                         } else {
1630                                 $s .= ', ';
1631                         }
1632                         $s .= "\"$name\":\"" .
1633                                 str_replace( '"', '\\"', $value->__toString() ) . '"';
1634                 }
1635                 $s .= '}';
1636                 return $s;
1637         }
1638
1639         /**
1640          * @return bool
1641          */
1642         function isEmpty() {
1643                 return !count( $this->args );
1644         }
1645
1646         function getArgument( $index ) {
1647                 if ( !isset( $this->args[$index] ) ) {
1648                         return false;
1649                 }
1650                 return $this->args[$index];
1651         }
1652
1653         function getArguments() {
1654                 return $this->args;
1655         }
1656 }
1657
1658 /**
1659  * @ingroup Parser
1660  */
1661 class PPNode_DOM implements PPNode {
1662         /** @var DOMElement */
1663         public $node;
1664
1665         /** @var DOMXPath */
1666         protected $xpath;
1667
1668         function __construct( $node, $xpath = false ) {
1669                 $this->node = $node;
1670         }
1671
1672         /**
1673          * @return DOMXPath
1674          */
1675         function getXPath() {
1676                 if ( $this->xpath === null ) {
1677                         $this->xpath = new DOMXPath( $this->node->ownerDocument );
1678                 }
1679                 return $this->xpath;
1680         }
1681
1682         function __toString() {
1683                 if ( $this->node instanceof DOMNodeList ) {
1684                         $s = '';
1685                         foreach ( $this->node as $node ) {
1686                                 $s .= $node->ownerDocument->saveXML( $node );
1687                         }
1688                 } else {
1689                         $s = $this->node->ownerDocument->saveXML( $this->node );
1690                 }
1691                 return $s;
1692         }
1693
1694         /**
1695          * @return bool|PPNode_DOM
1696          */
1697         function getChildren() {
1698                 return $this->node->childNodes ? new self( $this->node->childNodes ) : false;
1699         }
1700
1701         /**
1702          * @return bool|PPNode_DOM
1703          */
1704         function getFirstChild() {
1705                 return $this->node->firstChild ? new self( $this->node->firstChild ) : false;
1706         }
1707
1708         /**
1709          * @return bool|PPNode_DOM
1710          */
1711         function getNextSibling() {
1712                 return $this->node->nextSibling ? new self( $this->node->nextSibling ) : false;
1713         }
1714
1715         /**
1716          * @param string $type
1717          *
1718          * @return bool|PPNode_DOM
1719          */
1720         function getChildrenOfType( $type ) {
1721                 return new self( $this->getXPath()->query( $type, $this->node ) );
1722         }
1723
1724         /**
1725          * @return int
1726          */
1727         function getLength() {
1728                 if ( $this->node instanceof DOMNodeList ) {
1729                         return $this->node->length;
1730                 } else {
1731                         return false;
1732                 }
1733         }
1734
1735         /**
1736          * @param int $i
1737          * @return bool|PPNode_DOM
1738          */
1739         function item( $i ) {
1740                 $item = $this->node->item( $i );
1741                 return $item ? new self( $item ) : false;
1742         }
1743
1744         /**
1745          * @return string
1746          */
1747         function getName() {
1748                 if ( $this->node instanceof DOMNodeList ) {
1749                         return '#nodelist';
1750                 } else {
1751                         return $this->node->nodeName;
1752                 }
1753         }
1754
1755         /**
1756          * Split a "<part>" node into an associative array containing:
1757          *  - name          PPNode name
1758          *  - index         String index
1759          *  - value         PPNode value
1760          *
1761          * @throws MWException
1762          * @return array
1763          */
1764         function splitArg() {
1765                 $xpath = $this->getXPath();
1766                 $names = $xpath->query( 'name', $this->node );
1767                 $values = $xpath->query( 'value', $this->node );
1768                 if ( !$names->length || !$values->length ) {
1769                         throw new MWException( 'Invalid brace node passed to ' . __METHOD__ );
1770                 }
1771                 $name = $names->item( 0 );
1772                 $index = $name->getAttribute( 'index' );
1773                 return array(
1774                         'name' => new self( $name ),
1775                         'index' => $index,
1776                         'value' => new self( $values->item( 0 ) ) );
1777         }
1778
1779         /**
1780          * Split an "<ext>" node into an associative array containing name, attr, inner and close
1781          * All values in the resulting array are PPNodes. Inner and close are optional.
1782          *
1783          * @throws MWException
1784          * @return array
1785          */
1786         function splitExt() {
1787                 $xpath = $this->getXPath();
1788                 $names = $xpath->query( 'name', $this->node );
1789                 $attrs = $xpath->query( 'attr', $this->node );
1790                 $inners = $xpath->query( 'inner', $this->node );
1791                 $closes = $xpath->query( 'close', $this->node );
1792                 if ( !$names->length || !$attrs->length ) {
1793                         throw new MWException( 'Invalid ext node passed to ' . __METHOD__ );
1794                 }
1795                 $parts = array(
1796                         'name' => new self( $names->item( 0 ) ),
1797                         'attr' => new self( $attrs->item( 0 ) ) );
1798                 if ( $inners->length ) {
1799                         $parts['inner'] = new self( $inners->item( 0 ) );
1800                 }
1801                 if ( $closes->length ) {
1802                         $parts['close'] = new self( $closes->item( 0 ) );
1803                 }
1804                 return $parts;
1805         }
1806
1807         /**
1808          * Split a "<h>" node
1809          * @throws MWException
1810          * @return array
1811          */
1812         function splitHeading() {
1813                 if ( $this->getName() !== 'h' ) {
1814                         throw new MWException( 'Invalid h node passed to ' . __METHOD__ );
1815                 }
1816                 return array(
1817                         'i' => $this->node->getAttribute( 'i' ),
1818                         'level' => $this->node->getAttribute( 'level' ),
1819                         'contents' => $this->getChildren()
1820                 );
1821         }
1822 }