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