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                 }
 187                 if ( $result ) {
 188                         $obj = new PPNode_DOM( $dom->documentElement );
 189                 }
 190                 wfProfileOut( __METHOD__ . '-loadXML' );
 191
 192                 if ( $cacheable ) {
 193                         wfProfileOut( __METHOD__ . '-cacheable' );
 194                 }
 195
 196                 wfProfileOut( __METHOD__ );
 197
 198                 if ( !$result ) {
 199                         throw new MWException( __METHOD__ . ' generated invalid XML' );
 200                 }
 201                 return $obj;
 202         }
 203
 204         /**
 205          * @param $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, " \t", $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, " \t", $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, " \t", $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
 409                                                                 && strspn( $accum, " \t", -$wsLength ) === $wsLength )
 410                                                         {
 411                                                                 $accum = substr( $accum, 0, -$wsLength );
 412                                                         }
 413
 414                                                         // Dump all but the last comment to the accumulator
 415                                                         foreach ( $comments as $j => $com ) {
 416                                                                 $startPos = $com[0];
 417                                                                 $endPos = $com[1] + 1;
 418                                                                 if ( $j == ( count( $comments ) - 1 ) ) {
 419                                                                         break;
 420                                                                 }
 421                                                                 $inner = substr( $text, $startPos, $endPos - $startPos );
 422                                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 423                                                         }
 424
 425                                                         // Do a line-start run next time to look for headings after the comment
 426                                                         $fakeLineStart = true;
 427                                                 } else {
 428                                                         // No line to eat, just take the comment itself
 429                                                         $startPos = $i;
 430                                                         $endPos += 2;
 431                                                 }
 432
 433                                                 if ( $stack->top ) {
 434                                                         $part = $stack->top->getCurrentPart();
 435                                                         if ( !( isset( $part->commentEnd ) && $part->commentEnd == $wsStart - 1 ) ) {
 436                                                                 $part->visualEnd = $wsStart;
 437                                                         }
 438                                                         // Else comments abutting, no change in visual end
 439                                                         $part->commentEnd = $endPos;
 440                                                 }
 441                                                 $i = $endPos + 1;
 442                                                 $inner = substr( $text, $startPos, $endPos - $startPos + 1 );
 443                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 444                                         }
 445                                         continue;
 446                                 }
 447                                 $name = $matches[1];
 448                                 $lowerName = strtolower( $name );
 449                                 $attrStart = $i + strlen( $name ) + 1;
 450
 451                                 // Find end of tag
 452                                 $tagEndPos = $noMoreGT ? false : strpos( $text, '>', $attrStart );
 453                                 if ( $tagEndPos === false ) {
 454                                         // Infinite backtrack
 455                                         // Disable tag search to prevent worst-case O(N^2) performance
 456                                         $noMoreGT = true;
 457                                         $accum .= '&lt;';
 458                                         ++$i;
 459                                         continue;
 460                                 }
 461
 462                                 // Handle ignored tags
 463                                 if ( in_array( $lowerName, $ignoredTags ) ) {
 464                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i, $tagEndPos - $i + 1 ) ) . '</ignore>';
 465                                         $i = $tagEndPos + 1;
 466                                         continue;
 467                                 }
 468
 469                                 $tagStartPos = $i;
 470                                 if ( $text[$tagEndPos - 1] == '/' ) {
 471                                         $attrEnd = $tagEndPos - 1;
 472                                         $inner = null;
 473                                         $i = $tagEndPos + 1;
 474                                         $close = '';
 475                                 } else {
 476                                         $attrEnd = $tagEndPos;
 477                                         // Find closing tag
 478                                         if ( preg_match( "/<\/" . preg_quote( $name, '/' ) . "\s*>/i",
 479                                                         $text, $matches, PREG_OFFSET_CAPTURE, $tagEndPos + 1 ) )
 480                                         {
 481                                                 $inner = substr( $text, $tagEndPos + 1, $matches[0][1] - $tagEndPos - 1 );
 482                                                 $i = $matches[0][1] + strlen( $matches[0][0] );
 483                                                 $close = '<close>' . htmlspecialchars( $matches[0][0] ) . '</close>';
 484                                         } else {
 485                                                 // No end tag -- let it run out to the end of the text.
 486                                                 $inner = substr( $text, $tagEndPos + 1 );
 487                                                 $i = $lengthText;
 488                                                 $close = '';
 489                                         }
 490                                 }
 491                                 // <includeonly> and <noinclude> just become <ignore> tags
 492                                 if ( in_array( $lowerName, $ignoredElements ) ) {
 493                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $tagStartPos, $i - $tagStartPos ) )
 494                                                 . '</ignore>';
 495                                         continue;
 496                                 }
 497
 498                                 $accum .= '<ext>';
 499                                 if ( $attrEnd <= $attrStart ) {
 500                                         $attr = '';
 501                                 } else {
 502                                         $attr = substr( $text, $attrStart, $attrEnd - $attrStart );
 503                                 }
 504                                 $accum .= '<name>' . htmlspecialchars( $name ) . '</name>' .
 505                                         // Note that the attr element contains the whitespace between name and attribute,
 506                                         // this is necessary for precise reconstruction during pre-save transform.
 507                                         '<attr>' . htmlspecialchars( $attr ) . '</attr>';
 508                                 if ( $inner !== null ) {
 509                                         $accum .= '<inner>' . htmlspecialchars( $inner ) . '</inner>';
 510                                 }
 511                                 $accum .= $close . '</ext>';
 512                         } elseif ( $found == 'line-start' ) {
 513                                 // Is this the start of a heading?
 514                                 // Line break belongs before the heading element in any case
 515                                 if ( $fakeLineStart ) {
 516                                         $fakeLineStart = false;
 517                                 } else {
 518                                         $accum .= $curChar;
 519                                         $i++;
 520                                 }
 521
 522                                 $count = strspn( $text, '=', $i, 6 );
 523                                 if ( $count == 1 && $findEquals ) {
 524                                         // DWIM: This looks kind of like a name/value separator
 525                                         // Let's let the equals handler have it and break the potential heading
 526                                         // This is heuristic, but AFAICT the methods for completely correct disambiguation are very complex.
 527                                 } elseif ( $count > 0 ) {
 528                                         $piece = array(
 529                                                 'open' => "\n",
 530                                                 'close' => "\n",
 531                                                 'parts' => array( new PPDPart( str_repeat( '=', $count ) ) ),
 532                                                 'startPos' => $i,
 533                                                 'count' => $count );
 534                                         $stack->push( $piece );
 535                                         $accum =& $stack->getAccum();
 536                                         $flags = $stack->getFlags();
 537                                         extract( $flags );
 538                                         $i += $count;
 539                                 }
 540                         } elseif ( $found == 'line-end' ) {
 541                                 $piece = $stack->top;
 542                                 // A heading must be open, otherwise \n wouldn't have been in the search list
 543                                 assert( '$piece->open == "\n"' );
 544                                 $part = $piece->getCurrentPart();
 545                                 // Search back through the input to see if it has a proper close
 546                                 // Do this using the reversed string since the other solutions (end anchor, etc.) are inefficient
 547                                 $wsLength = strspn( $revText, " \t", $lengthText - $i );
 548                                 $searchStart = $i - $wsLength;
 549                                 if ( isset( $part->commentEnd ) && $searchStart - 1 == $part->commentEnd ) {
 550                                         // Comment found at line end
 551                                         // Search for equals signs before the comment
 552                                         $searchStart = $part->visualEnd;
 553                                         $searchStart -= strspn( $revText, " \t", $lengthText - $searchStart );
 554                                 }
 555                                 $count = $piece->count;
 556                                 $equalsLength = strspn( $revText, '=', $lengthText - $searchStart );
 557                                 if ( $equalsLength > 0 ) {
 558                                         if ( $searchStart - $equalsLength == $piece->startPos ) {
 559                                                 // This is just a single string of equals signs on its own line
 560                                                 // Replicate the doHeadings behavior /={count}(.+)={count}/
 561                                                 // First find out how many equals signs there really are (don't stop at 6)
 562                                                 $count = $equalsLength;
 563                                                 if ( $count < 3 ) {
 564                                                         $count = 0;
 565                                                 } else {
 566                                                         $count = min( 6, intval( ( $count - 1 ) / 2 ) );
 567                                                 }
 568                                         } else {
 569                                                 $count = min( $equalsLength, $count );
 570                                         }
 571                                         if ( $count > 0 ) {
 572                                                 // Normal match, output <h>
 573                                                 $element = "<h level=\"$count\" i=\"$headingIndex\">$accum</h>";
 574                                                 $headingIndex++;
 575                                         } else {
 576                                                 // Single equals sign on its own line, count=0
 577                                                 $element = $accum;
 578                                         }
 579                                 } else {
 580                                         // No match, no <h>, just pass down the inner text
 581                                         $element = $accum;
 582                                 }
 583                                 // Unwind the stack
 584                                 $stack->pop();
 585                                 $accum =& $stack->getAccum();
 586                                 $flags = $stack->getFlags();
 587                                 extract( $flags );
 588
 589                                 // Append the result to the enclosing accumulator
 590                                 $accum .= $element;
 591                                 // Note that we do NOT increment the input pointer.
 592                                 // This is because the closing linebreak could be the opening linebreak of
 593                                 // another heading. Infinite loops are avoided because the next iteration MUST
 594                                 // hit the heading open case above, which unconditionally increments the
 595                                 // input pointer.
 596                         } elseif ( $found == 'open' ) {
 597                                 # count opening brace characters
 598                                 $count = strspn( $text, $curChar, $i );
 599
 600                                 # we need to add to stack only if opening brace count is enough for one of the rules
 601                                 if ( $count >= $rule['min'] ) {
 602                                         # Add it to the stack
 603                                         $piece = array(
 604                                                 'open' => $curChar,
 605                                                 'close' => $rule['end'],
 606                                                 'count' => $count,
 607                                                 'lineStart' => ( $i > 0 && $text[$i - 1] == "\n" ),
 608                                         );
 609
 610                                         $stack->push( $piece );
 611                                         $accum =& $stack->getAccum();
 612                                         $flags = $stack->getFlags();
 613                                         extract( $flags );
 614                                 } else {
 615                                         # Add literal brace(s)
 616                                         $accum .= htmlspecialchars( str_repeat( $curChar, $count ) );
 617                                 }
 618                                 $i += $count;
 619                         } elseif ( $found == 'close' ) {
 620                                 $piece = $stack->top;
 621                                 # lets check if there are enough characters for closing brace
 622                                 $maxCount = $piece->count;
 623                                 $count = strspn( $text, $curChar, $i, $maxCount );
 624
 625                                 # check for maximum matching characters (if there are 5 closing
 626                                 # characters, we will probably need only 3 - depending on the rules)
 627                                 $rule = $rules[$piece->open];
 628                                 if ( $count > $rule['max'] ) {
 629                                         # The specified maximum exists in the callback array, unless the caller
 630                                         # has made an error
 631                                         $matchingCount = $rule['max'];
 632                                 } else {
 633                                         # Count is less than the maximum
 634                                         # Skip any gaps in the callback array to find the true largest match
 635                                         # Need to use array_key_exists not isset because the callback can be null
 636                                         $matchingCount = $count;
 637                                         while ( $matchingCount > 0 && !array_key_exists( $matchingCount, $rule['names'] ) ) {
 638                                                 --$matchingCount;
 639                                         }
 640                                 }
 641
 642                                 if ( $matchingCount <= 0 ) {
 643                                         # No matching element found in callback array
 644                                         # Output a literal closing brace and continue
 645                                         $accum .= htmlspecialchars( str_repeat( $curChar, $count ) );
 646                                         $i += $count;
 647                                         continue;
 648                                 }
 649                                 $name = $rule['names'][$matchingCount];
 650                                 if ( $name === null ) {
 651                                         // No element, just literal text
 652                                         $element = $piece->breakSyntax( $matchingCount ) . str_repeat( $rule['end'], $matchingCount );
 653                                 } else {
 654                                         # Create XML element
 655                                         # Note: $parts is already XML, does not need to be encoded further
 656                                         $parts = $piece->parts;
 657                                         $title = $parts[0]->out;
 658                                         unset( $parts[0] );
 659
 660                                         # The invocation is at the start of the line if lineStart is set in
 661                                         # the stack, and all opening brackets are used up.
 662                                         if ( $maxCount == $matchingCount && !empty( $piece->lineStart ) ) {
 663                                                 $attr = ' lineStart="1"';
 664                                         } else {
 665                                                 $attr = '';
 666                                         }
 667
 668                                         $element = "<$name$attr>";
 669                                         $element .= "<title>$title</title>";
 670                                         $argIndex = 1;
 671                                         foreach ( $parts as $part ) {
 672                                                 if ( isset( $part->eqpos ) ) {
 673                                                         $argName = substr( $part->out, 0, $part->eqpos );
 674                                                         $argValue = substr( $part->out, $part->eqpos + 1 );
 675                                                         $element .= "<part><name>$argName</name>=<value>$argValue</value></part>";
 676                                                 } else {
 677                                                         $element .= "<part><name index=\"$argIndex\" /><value>{$part->out}</value></part>";
 678                                                         $argIndex++;
 679                                                 }
 680                                         }
 681                                         $element .= "</$name>";
 682                                 }
 683
 684                                 # Advance input pointer
 685                                 $i += $matchingCount;
 686
 687                                 # Unwind the stack
 688                                 $stack->pop();
 689                                 $accum =& $stack->getAccum();
 690
 691                                 # Re-add the old stack element if it still has unmatched opening characters remaining
 692                                 if ( $matchingCount < $piece->count ) {
 693                                         $piece->parts = array( new PPDPart );
 694                                         $piece->count -= $matchingCount;
 695                                         # do we still qualify for any callback with remaining count?
 696                                         $min = $rules[$piece->open]['min'];
 697                                         if ( $piece->count >= $min ) {
 698                                                 $stack->push( $piece );
 699                                                 $accum =& $stack->getAccum();
 700                                         } else {
 701                                                 $accum .= str_repeat( $piece->open, $piece->count );
 702                                         }
 703                                 }
 704                                 $flags = $stack->getFlags();
 705                                 extract( $flags );
 706
 707                                 # Add XML element to the enclosing accumulator
 708                                 $accum .= $element;
 709                         } elseif ( $found == 'pipe' ) {
 710                                 $findEquals = true; // shortcut for getFlags()
 711                                 $stack->addPart();
 712                                 $accum =& $stack->getAccum();
 713                                 ++$i;
 714                         } elseif ( $found == 'equals' ) {
 715                                 $findEquals = false; // shortcut for getFlags()
 716                                 $stack->getCurrentPart()->eqpos = strlen( $accum );
 717                                 $accum .= '=';
 718                                 ++$i;
 719                         }
 720                 }
 721
 722                 # Output any remaining unclosed brackets
 723                 foreach ( $stack->stack as $piece ) {
 724                         $stack->rootAccum .= $piece->breakSyntax();
 725                 }
 726                 $stack->rootAccum .= '</root>';
 727                 $xml = $stack->rootAccum;
 728
 729                 wfProfileOut( __METHOD__ );
 730
 731                 return $xml;
 732         }
 733 }
 734
 735 /**
 736  * Stack class to help Preprocessor::preprocessToObj()
 737  * @ingroup Parser
 738  */
 739 class PPDStack {
 740         var $stack, $rootAccum;
 741
 742         /**
 743          * @var PPDStack
 744          */
 745         var $top;
 746         var $out;
 747         var $elementClass = 'PPDStackElement';
 748
 749         static $false = false;
 750
 751         function __construct() {
 752                 $this->stack = array();
 753                 $this->top = false;
 754                 $this->rootAccum = '';
 755                 $this->accum =& $this->rootAccum;
 756         }
 757
 758         /**
 759          * @return int
 760          */
 761         function count() {
 762                 return count( $this->stack );
 763         }
 764
 765         function &getAccum() {
 766                 return $this->accum;
 767         }
 768
 769         function getCurrentPart() {
 770                 if ( $this->top === false ) {
 771                         return false;
 772                 } else {
 773                         return $this->top->getCurrentPart();
 774                 }
 775         }
 776
 777         function push( $data ) {
 778                 if ( $data instanceof $this->elementClass ) {
 779                         $this->stack[] = $data;
 780                 } else {
 781                         $class = $this->elementClass;
 782                         $this->stack[] = new $class( $data );
 783                 }
 784                 $this->top = $this->stack[count( $this->stack ) - 1];
 785                 $this->accum =& $this->top->getAccum();
 786         }
 787
 788         function pop() {
 789                 if ( !count( $this->stack ) ) {
 790                         throw new MWException( __METHOD__ . ': no elements remaining' );
 791                 }
 792                 $temp = array_pop( $this->stack );
 793
 794                 if ( count( $this->stack ) ) {
 795                         $this->top = $this->stack[count( $this->stack ) - 1];
 796                         $this->accum =& $this->top->getAccum();
 797                 } else {
 798                         $this->top = self::$false;
 799                         $this->accum =& $this->rootAccum;
 800                 }
 801                 return $temp;
 802         }
 803
 804         function addPart( $s = '' ) {
 805                 $this->top->addPart( $s );
 806                 $this->accum =& $this->top->getAccum();
 807         }
 808
 809         /**
 810          * @return array
 811          */
 812         function getFlags() {
 813                 if ( !count( $this->stack ) ) {
 814                         return array(
 815                                 'findEquals' => false,
 816                                 'findPipe' => false,
 817                                 'inHeading' => false,
 818                         );
 819                 } else {
 820                         return $this->top->getFlags();
 821                 }
 822         }
 823 }
 824
 825 /**
 826  * @ingroup Parser
 827  */
 828 class PPDStackElement {
 829         var     $open,              // Opening character (\n for heading)
 830                 $close,             // Matching closing character
 831                 $count,             // Number of opening characters found (number of "=" for heading)
 832                 $parts,             // Array of PPDPart objects describing pipe-separated parts.
 833                 $lineStart;         // True if the open char appeared at the start of the input line. Not set for headings.
 834
 835         var $partClass = 'PPDPart';
 836
 837         function __construct( $data = array() ) {
 838                 $class = $this->partClass;
 839                 $this->parts = array( new $class );
 840
 841                 foreach ( $data as $name => $value ) {
 842                         $this->$name = $value;
 843                 }
 844         }
 845
 846         function &getAccum() {
 847                 return $this->parts[count( $this->parts ) - 1]->out;
 848         }
 849
 850         function addPart( $s = '' ) {
 851                 $class = $this->partClass;
 852                 $this->parts[] = new $class( $s );
 853         }
 854
 855         function getCurrentPart() {
 856                 return $this->parts[count( $this->parts ) - 1];
 857         }
 858
 859         /**
 860          * @return array
 861          */
 862         function getFlags() {
 863                 $partCount = count( $this->parts );
 864                 $findPipe = $this->open != "\n" && $this->open != '[';
 865                 return array(
 866                         'findPipe' => $findPipe,
 867                         'findEquals' => $findPipe && $partCount > 1 && !isset( $this->parts[$partCount - 1]->eqpos ),
 868                         'inHeading' => $this->open == "\n",
 869                 );
 870         }
 871
 872         /**
 873          * Get the output string that would result if the close is not found.
 874          *
 875          * @return string
 876          */
 877         function breakSyntax( $openingCount = false ) {
 878                 if ( $this->open == "\n" ) {
 879                         $s = $this->parts[0]->out;
 880                 } else {
 881                         if ( $openingCount === false ) {
 882                                 $openingCount = $this->count;
 883                         }
 884                         $s = str_repeat( $this->open, $openingCount );
 885                         $first = true;
 886                         foreach ( $this->parts as $part ) {
 887                                 if ( $first ) {
 888                                         $first = false;
 889                                 } else {
 890                                         $s .= '|';
 891                                 }
 892                                 $s .= $part->out;
 893                         }
 894                 }
 895                 return $s;
 896         }
 897 }
 898
 899 /**
 900  * @ingroup Parser
 901  */
 902 class PPDPart {
 903         var $out; // Output accumulator string
 904
 905         // Optional member variables:
 906         //   eqpos        Position of equals sign in output accumulator
 907         //   commentEnd   Past-the-end input pointer for the last comment encountered
 908         //   visualEnd    Past-the-end input pointer for the end of the accumulator minus comments
 909
 910         function __construct( $out = '' ) {
 911                 $this->out = $out;
 912         }
 913 }
 914
 915 /**
 916  * An expansion frame, used as a context to expand the result of preprocessToObj()
 917  * @ingroup Parser
 918  */
 919 class PPFrame_DOM implements PPFrame {
 920
 921         /**
 922          * @var Preprocessor
 923          */
 924         var $preprocessor;
 925
 926         /**
 927          * @var Parser
 928          */
 929         var $parser;
 930
 931         /**
 932          * @var Title
 933          */
 934         var $title;
 935         var $titleCache;
 936
 937         /**
 938          * Hashtable listing templates which are disallowed for expansion in this frame,
 939          * having been encountered previously in parent frames.
 940          */
 941         var $loopCheckHash;
 942
 943         /**
 944          * Recursion depth of this frame, top = 0
 945          * Note that this is NOT the same as expansion depth in expand()
 946          */
 947         var $depth;
 948
 949         /**
 950          * Construct a new preprocessor frame.
 951          * @param $preprocessor Preprocessor The parent preprocessor
 952          */
 953         function __construct( $preprocessor ) {
 954                 $this->preprocessor = $preprocessor;
 955                 $this->parser = $preprocessor->parser;
 956                 $this->title = $this->parser->mTitle;
 957                 $this->titleCache = array( $this->title ? $this->title->getPrefixedDBkey() : false );
 958                 $this->loopCheckHash = array();
 959                 $this->depth = 0;
 960         }
 961
 962         /**
 963          * Create a new child frame
 964          * $args is optionally a multi-root PPNode or array containing the template arguments
 965          *
 966          * @return PPTemplateFrame_DOM
 967          */
 968         function newChild( $args = false, $title = false, $indexOffset = 0 ) {
 969                 $namedArgs = array();
 970                 $numberedArgs = array();
 971                 if ( $title === false ) {
 972                         $title = $this->title;
 973                 }
 974                 if ( $args !== false ) {
 975                         $xpath = false;
 976                         if ( $args instanceof PPNode ) {
 977                                 $args = $args->node;
 978                         }
 979                         foreach ( $args as $arg ) {
 980                                 if ( $arg instanceof PPNode ) {
 981                                         $arg = $arg->node;
 982                                 }
 983                                 if ( !$xpath ) {
 984                                         $xpath = new DOMXPath( $arg->ownerDocument );
 985                                 }
 986
 987                                 $nameNodes = $xpath->query( 'name', $arg );
 988                                 $value = $xpath->query( 'value', $arg );
 989                                 if ( $nameNodes->item( 0 )->hasAttributes() ) {
 990                                         // Numbered parameter
 991                                         $index = $nameNodes->item( 0 )->attributes->getNamedItem( 'index' )->textContent;
 992                                         $index = $index - $indexOffset;
 993                                         $numberedArgs[$index] = $value->item( 0 );
 994                                         unset( $namedArgs[$index] );
 995                                 } else {
 996                                         // Named parameter
 997                                         $name = trim( $this->expand( $nameNodes->item( 0 ), PPFrame::STRIP_COMMENTS ) );
 998                                         $namedArgs[$name] = $value->item( 0 );
 999                                         unset( $numberedArgs[$name] );
1000                                 }
1001                         }
1002                 }
1003                 return new PPTemplateFrame_DOM( $this->preprocessor, $this, $numberedArgs, $namedArgs, $title );
1004         }
1005
1006         /**
1007          * @throws MWException
1008          * @param $root
1009          * @param $flags int
1010          * @return string
1011          */
1012         function expand( $root, $flags = 0 ) {
1013                 static $expansionDepth = 0;
1014                 if ( is_string( $root ) ) {
1015                         return $root;
1016                 }
1017
1018                 if ( ++$this->parser->mPPNodeCount > $this->parser->mOptions->getMaxPPNodeCount() ) {
1019                         $this->parser->limitationWarn( 'node-count-exceeded',
1020                                 $this->parser->mPPNodeCount,
1021                                 $this->parser->mOptions->getMaxPPNodeCount()
1022                         );
1023                         return '<span class="error">Node-count limit exceeded</span>';
1024                 }
1025
1026                 if ( $expansionDepth > $this->parser->mOptions->getMaxPPExpandDepth() ) {
1027                         $this->parser->limitationWarn( 'expansion-depth-exceeded',
1028                                 $expansionDepth,
1029                                 $this->parser->mOptions->getMaxPPExpandDepth()
1030                         );
1031                         return '<span class="error">Expansion depth limit exceeded</span>';
1032                 }
1033                 wfProfileIn( __METHOD__ );
1034                 ++$expansionDepth;
1035                 if ( $expansionDepth > $this->parser->mHighestExpansionDepth ) {
1036                         $this->parser->mHighestExpansionDepth = $expansionDepth;
1037                 }
1038
1039                 if ( $root instanceof PPNode_DOM ) {
1040                         $root = $root->node;
1041                 }
1042                 if ( $root instanceof DOMDocument ) {
1043                         $root = $root->documentElement;
1044                 }
1045
1046                 $outStack = array( '', '' );
1047                 $iteratorStack = array( false, $root );
1048                 $indexStack = array( 0, 0 );
1049
1050                 while ( count( $iteratorStack ) > 1 ) {
1051                         $level = count( $outStack ) - 1;
1052                         $iteratorNode =& $iteratorStack[$level];
1053                         $out =& $outStack[$level];
1054                         $index =& $indexStack[$level];
1055
1056                         if ( $iteratorNode instanceof PPNode_DOM ) {
1057                                 $iteratorNode = $iteratorNode->node;
1058                         }
1059
1060                         if ( is_array( $iteratorNode ) ) {
1061                                 if ( $index >= count( $iteratorNode ) ) {
1062                                         // All done with this iterator
1063                                         $iteratorStack[$level] = false;
1064                                         $contextNode = false;
1065                                 } else {
1066                                         $contextNode = $iteratorNode[$index];
1067                                         $index++;
1068                                 }
1069                         } elseif ( $iteratorNode instanceof DOMNodeList ) {
1070                                 if ( $index >= $iteratorNode->length ) {
1071                                         // All done with this iterator
1072                                         $iteratorStack[$level] = false;
1073                                         $contextNode = false;
1074                                 } else {
1075                                         $contextNode = $iteratorNode->item( $index );
1076                                         $index++;
1077                                 }
1078                         } else {
1079                                 // Copy to $contextNode and then delete from iterator stack,
1080                                 // because this is not an iterator but we do have to execute it once
1081                                 $contextNode = $iteratorStack[$level];
1082                                 $iteratorStack[$level] = false;
1083                         }
1084
1085                         if ( $contextNode instanceof PPNode_DOM ) {
1086                                 $contextNode = $contextNode->node;
1087                         }
1088
1089                         $newIterator = false;
1090
1091                         if ( $contextNode === false ) {
1092                                 // nothing to do
1093                         } elseif ( is_string( $contextNode ) ) {
1094                                 $out .= $contextNode;
1095                         } elseif ( is_array( $contextNode ) || $contextNode instanceof DOMNodeList ) {
1096                                 $newIterator = $contextNode;
1097                         } elseif ( $contextNode instanceof DOMNode ) {
1098                                 if ( $contextNode->nodeType == XML_TEXT_NODE ) {
1099                                         $out .= $contextNode->nodeValue;
1100                                 } elseif ( $contextNode->nodeName == 'template' ) {
1101                                         # Double-brace expansion
1102                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1103                                         $titles = $xpath->query( 'title', $contextNode );
1104                                         $title = $titles->item( 0 );
1105                                         $parts = $xpath->query( 'part', $contextNode );
1106                                         if ( $flags & PPFrame::NO_TEMPLATES ) {
1107                                                 $newIterator = $this->virtualBracketedImplode( '{{', '|', '}}', $title, $parts );
1108                                         } else {
1109                                                 $lineStart = $contextNode->getAttribute( 'lineStart' );
1110                                                 $params = array(
1111                                                         'title' => new PPNode_DOM( $title ),
1112                                                         'parts' => new PPNode_DOM( $parts ),
1113                                                         'lineStart' => $lineStart );
1114                                                 $ret = $this->parser->braceSubstitution( $params, $this );
1115                                                 if ( isset( $ret['object'] ) ) {
1116                                                         $newIterator = $ret['object'];
1117                                                 } else {
1118                                                         $out .= $ret['text'];
1119                                                 }
1120                                         }
1121                                 } elseif ( $contextNode->nodeName == 'tplarg' ) {
1122                                         # Triple-brace expansion
1123                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1124                                         $titles = $xpath->query( 'title', $contextNode );
1125                                         $title = $titles->item( 0 );
1126                                         $parts = $xpath->query( 'part', $contextNode );
1127                                         if ( $flags & PPFrame::NO_ARGS ) {
1128                                                 $newIterator = $this->virtualBracketedImplode( '{{{', '|', '}}}', $title, $parts );
1129                                         } else {
1130                                                 $params = array(
1131                                                         'title' => new PPNode_DOM( $title ),
1132                                                         'parts' => new PPNode_DOM( $parts ) );
1133                                                 $ret = $this->parser->argSubstitution( $params, $this );
1134                                                 if ( isset( $ret['object'] ) ) {
1135                                                         $newIterator = $ret['object'];
1136                                                 } else {
1137                                                         $out .= $ret['text'];
1138                                                 }
1139                                         }
1140                                 } elseif ( $contextNode->nodeName == 'comment' ) {
1141                                         # HTML-style comment
1142                                         # Remove it in HTML, pre+remove and STRIP_COMMENTS modes
1143                                         if ( $this->parser->ot['html']
1144                                                 || ( $this->parser->ot['pre'] && $this->parser->mOptions->getRemoveComments() )
1145                                                 || ( $flags & PPFrame::STRIP_COMMENTS ) )
1146                                         {
1147                                                 $out .= '';
1148                                         }
1149                                         # Add a strip marker in PST mode so that pstPass2() can run some old-fashioned regexes on the result
1150                                         # Not in RECOVER_COMMENTS mode (extractSections) though
1151                                         elseif ( $this->parser->ot['wiki'] && !( $flags & PPFrame::RECOVER_COMMENTS ) ) {
1152                                                 $out .= $this->parser->insertStripItem( $contextNode->textContent );
1153                                         }
1154                                         # Recover the literal comment in RECOVER_COMMENTS and pre+no-remove
1155                                         else {
1156                                                 $out .= $contextNode->textContent;
1157                                         }
1158                                 } elseif ( $contextNode->nodeName == 'ignore' ) {
1159                                         # Output suppression used by <includeonly> etc.
1160                                         # OT_WIKI will only respect <ignore> in substed templates.
1161                                         # The other output types respect it unless NO_IGNORE is set.
1162                                         # extractSections() sets NO_IGNORE and so never respects it.
1163                                         if ( ( !isset( $this->parent ) && $this->parser->ot['wiki'] ) || ( $flags & PPFrame::NO_IGNORE ) ) {
1164                                                 $out .= $contextNode->textContent;
1165                                         } else {
1166                                                 $out .= '';
1167                                         }
1168                                 } elseif ( $contextNode->nodeName == 'ext' ) {
1169                                         # Extension tag
1170                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1171                                         $names = $xpath->query( 'name', $contextNode );
1172                                         $attrs = $xpath->query( 'attr', $contextNode );
1173                                         $inners = $xpath->query( 'inner', $contextNode );
1174                                         $closes = $xpath->query( 'close', $contextNode );
1175                                         $params = array(
1176                                                 'name' => new PPNode_DOM( $names->item( 0 ) ),
1177                                                 'attr' => $attrs->length > 0 ? new PPNode_DOM( $attrs->item( 0 ) ) : null,
1178                                                 'inner' => $inners->length > 0 ? new PPNode_DOM( $inners->item( 0 ) ) : null,
1179                                                 'close' => $closes->length > 0 ? new PPNode_DOM( $closes->item( 0 ) ) : null,
1180                                         );
1181                                         $out .= $this->parser->extensionSubstitution( $params, $this );
1182                                 } elseif ( $contextNode->nodeName == 'h' ) {
1183                                         # Heading
1184                                         $s = $this->expand( $contextNode->childNodes, $flags );
1185
1186                                         # Insert a heading marker only for <h> children of <root>
1187                                         # This is to stop extractSections from going over multiple tree levels
1188                                         if ( $contextNode->parentNode->nodeName == 'root' && $this->parser->ot['html'] ) {
1189                                                 # Insert heading index marker
1190                                                 $headingIndex = $contextNode->getAttribute( 'i' );
1191                                                 $titleText = $this->title->getPrefixedDBkey();
1192                                                 $this->parser->mHeadings[] = array( $titleText, $headingIndex );
1193                                                 $serial = count( $this->parser->mHeadings ) - 1;
1194                                                 $marker = "{$this->parser->mUniqPrefix}-h-$serial-" . Parser::MARKER_SUFFIX;
1195                                                 $count = $contextNode->getAttribute( 'level' );
1196                                                 $s = substr( $s, 0, $count ) . $marker . substr( $s, $count );
1197                                                 $this->parser->mStripState->addGeneral( $marker, '' );
1198                                         }
1199                                         $out .= $s;
1200                                 } else {
1201                                         # Generic recursive expansion
1202                                         $newIterator = $contextNode->childNodes;
1203                                 }
1204                         } else {
1205                                 wfProfileOut( __METHOD__ );
1206                                 throw new MWException( __METHOD__ . ': Invalid parameter type' );
1207                         }
1208
1209                         if ( $newIterator !== false ) {
1210                                 if ( $newIterator instanceof PPNode_DOM ) {
1211                                         $newIterator = $newIterator->node;
1212                                 }
1213                                 $outStack[] = '';
1214                                 $iteratorStack[] = $newIterator;
1215                                 $indexStack[] = 0;
1216                         } elseif ( $iteratorStack[$level] === false ) {
1217                                 // Return accumulated value to parent
1218                                 // With tail recursion
1219                                 while ( $iteratorStack[$level] === false && $level > 0 ) {
1220                                         $outStack[$level - 1] .= $out;
1221                                         array_pop( $outStack );
1222                                         array_pop( $iteratorStack );
1223                                         array_pop( $indexStack );
1224                                         $level--;
1225                                 }
1226                         }
1227                 }
1228                 --$expansionDepth;
1229                 wfProfileOut( __METHOD__ );
1230                 return $outStack[0];
1231         }
1232
1233         /**
1234          * @param $sep
1235          * @param $flags
1236          * @return string
1237          */
1238         function implodeWithFlags( $sep, $flags /*, ... */ ) {
1239                 $args = array_slice( func_get_args(), 2 );
1240
1241                 $first = true;
1242                 $s = '';
1243                 foreach ( $args as $root ) {
1244                         if ( $root instanceof PPNode_DOM ) {
1245                                 $root = $root->node;
1246                         }
1247                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1248                                 $root = array( $root );
1249                         }
1250                         foreach ( $root as $node ) {
1251                                 if ( $first ) {
1252                                         $first = false;
1253                                 } else {
1254                                         $s .= $sep;
1255                                 }
1256                                 $s .= $this->expand( $node, $flags );
1257                         }
1258                 }
1259                 return $s;
1260         }
1261
1262         /**
1263          * Implode with no flags specified
1264          * This previously called implodeWithFlags but has now been inlined to reduce stack depth
1265          *
1266          * @return string
1267          */
1268         function implode( $sep /*, ... */ ) {
1269                 $args = array_slice( func_get_args(), 1 );
1270
1271                 $first = true;
1272                 $s = '';
1273                 foreach ( $args as $root ) {
1274                         if ( $root instanceof PPNode_DOM ) {
1275                                 $root = $root->node;
1276                         }
1277                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1278                                 $root = array( $root );
1279                         }
1280                         foreach ( $root as $node ) {
1281                                 if ( $first ) {
1282                                         $first = false;
1283                                 } else {
1284                                         $s .= $sep;
1285                                 }
1286                                 $s .= $this->expand( $node );
1287                         }
1288                 }
1289                 return $s;
1290         }
1291
1292         /**
1293          * Makes an object that, when expand()ed, will be the same as one obtained
1294          * with implode()
1295          *
1296          * @return array
1297          */
1298         function virtualImplode( $sep /*, ... */ ) {
1299                 $args = array_slice( func_get_args(), 1 );
1300                 $out = array();
1301                 $first = true;
1302
1303                 foreach ( $args as $root ) {
1304                         if ( $root instanceof PPNode_DOM ) {
1305                                 $root = $root->node;
1306                         }
1307                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1308                                 $root = array( $root );
1309                         }
1310                         foreach ( $root as $node ) {
1311                                 if ( $first ) {
1312                                         $first = false;
1313                                 } else {
1314                                         $out[] = $sep;
1315                                 }
1316                                 $out[] = $node;
1317                         }
1318                 }
1319                 return $out;
1320         }
1321
1322         /**
1323          * Virtual implode with brackets
1324          * @return array
1325          */
1326         function virtualBracketedImplode( $start, $sep, $end /*, ... */ ) {
1327                 $args = array_slice( func_get_args(), 3 );
1328                 $out = array( $start );
1329                 $first = true;
1330
1331                 foreach ( $args as $root ) {
1332                         if ( $root instanceof PPNode_DOM ) {
1333                                 $root = $root->node;
1334                         }
1335                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1336                                 $root = array( $root );
1337                         }
1338                         foreach ( $root as $node ) {
1339                                 if ( $first ) {
1340                                         $first = false;
1341                                 } else {
1342                                         $out[] = $sep;
1343                                 }
1344                                 $out[] = $node;
1345                         }
1346                 }
1347                 $out[] = $end;
1348                 return $out;
1349         }
1350
1351         function __toString() {
1352                 return 'frame{}';
1353         }
1354
1355         function getPDBK( $level = false ) {
1356                 if ( $level === false ) {
1357                         return $this->title->getPrefixedDBkey();
1358                 } else {
1359                         return isset( $this->titleCache[$level] ) ? $this->titleCache[$level] : false;
1360                 }
1361         }
1362
1363         /**
1364          * @return array
1365          */
1366         function getArguments() {
1367                 return array();
1368         }
1369
1370         /**
1371          * @return array
1372          */
1373         function getNumberedArguments() {
1374                 return array();
1375         }
1376
1377         /**
1378          * @return array
1379          */
1380         function getNamedArguments() {
1381                 return array();
1382         }
1383
1384         /**
1385          * Returns true if there are no arguments in this frame
1386          *
1387          * @return bool
1388          */
1389         function isEmpty() {
1390                 return true;
1391         }
1392
1393         function getArgument( $name ) {
1394                 return false;
1395         }
1396
1397         /**
1398          * Returns true if the infinite loop check is OK, false if a loop is detected
1399          *
1400          * @return bool
1401          */
1402         function loopCheck( $title ) {
1403                 return !isset( $this->loopCheckHash[$title->getPrefixedDBkey()] );
1404         }
1405
1406         /**
1407          * Return true if the frame is a template frame
1408          *
1409          * @return bool
1410          */
1411         function isTemplate() {
1412                 return false;
1413         }
1414
1415         /**
1416          * Get a title of frame
1417          *
1418          * @return Title
1419          */
1420         function getTitle() {
1421                 return $this->title;
1422         }
1423 }
1424
1425 /**
1426  * Expansion frame with template arguments
1427  * @ingroup Parser
1428  */
1429 class PPTemplateFrame_DOM extends PPFrame_DOM {
1430         var $numberedArgs, $namedArgs;
1431
1432         /**
1433          * @var PPFrame_DOM
1434          */
1435         var $parent;
1436         var $numberedExpansionCache, $namedExpansionCache;
1437
1438         /**
1439          * @param $preprocessor
1440          * @param $parent PPFrame_DOM
1441          * @param $numberedArgs array
1442          * @param $namedArgs array
1443          * @param $title Title
1444          */
1445         function __construct( $preprocessor, $parent = false, $numberedArgs = array(), $namedArgs = array(), $title = false ) {
1446                 parent::__construct( $preprocessor );
1447
1448                 $this->parent = $parent;
1449                 $this->numberedArgs = $numberedArgs;
1450                 $this->namedArgs = $namedArgs;
1451                 $this->title = $title;
1452                 $pdbk = $title ? $title->getPrefixedDBkey() : false;
1453                 $this->titleCache = $parent->titleCache;
1454                 $this->titleCache[] = $pdbk;
1455                 $this->loopCheckHash = /*clone*/ $parent->loopCheckHash;
1456                 if ( $pdbk !== false ) {
1457                         $this->loopCheckHash[$pdbk] = true;
1458                 }
1459                 $this->depth = $parent->depth + 1;
1460                 $this->numberedExpansionCache = $this->namedExpansionCache = array();
1461         }
1462
1463         function __toString() {
1464                 $s = 'tplframe{';
1465                 $first = true;
1466                 $args = $this->numberedArgs + $this->namedArgs;
1467                 foreach ( $args as $name => $value ) {
1468                         if ( $first ) {
1469                                 $first = false;
1470                         } else {
1471                                 $s .= ', ';
1472                         }
1473                         $s .= "\"$name\":\"" .
1474                                 str_replace( '"', '\\"', $value->ownerDocument->saveXML( $value ) ) . '"';
1475                 }
1476                 $s .= '}';
1477                 return $s;
1478         }
1479
1480         /**
1481          * Returns true if there are no arguments in this frame
1482          *
1483          * @return bool
1484          */
1485         function isEmpty() {
1486                 return !count( $this->numberedArgs ) && !count( $this->namedArgs );
1487         }
1488
1489         function getArguments() {
1490                 $arguments = array();
1491                 foreach ( array_merge(
1492                                 array_keys( $this->numberedArgs ),
1493                                 array_keys( $this->namedArgs ) ) as $key ) {
1494                         $arguments[$key] = $this->getArgument( $key );
1495                 }
1496                 return $arguments;
1497         }
1498
1499         function getNumberedArguments() {
1500                 $arguments = array();
1501                 foreach ( array_keys( $this->numberedArgs ) as $key ) {
1502                         $arguments[$key] = $this->getArgument( $key );
1503                 }
1504                 return $arguments;
1505         }
1506
1507         function getNamedArguments() {
1508                 $arguments = array();
1509                 foreach ( array_keys( $this->namedArgs ) as $key ) {
1510                         $arguments[$key] = $this->getArgument( $key );
1511                 }
1512                 return $arguments;
1513         }
1514
1515         function getNumberedArgument( $index ) {
1516                 if ( !isset( $this->numberedArgs[$index] ) ) {
1517                         return false;
1518                 }
1519                 if ( !isset( $this->numberedExpansionCache[$index] ) ) {
1520                         # No trimming for unnamed arguments
1521                         $this->numberedExpansionCache[$index] = $this->parent->expand( $this->numberedArgs[$index], PPFrame::STRIP_COMMENTS );
1522                 }
1523                 return $this->numberedExpansionCache[$index];
1524         }
1525
1526         function getNamedArgument( $name ) {
1527                 if ( !isset( $this->namedArgs[$name] ) ) {
1528                         return false;
1529                 }
1530                 if ( !isset( $this->namedExpansionCache[$name] ) ) {
1531                         # Trim named arguments post-expand, for backwards compatibility
1532                         $this->namedExpansionCache[$name] = trim(
1533                                 $this->parent->expand( $this->namedArgs[$name], PPFrame::STRIP_COMMENTS ) );
1534                 }
1535                 return $this->namedExpansionCache[$name];
1536         }
1537
1538         function getArgument( $name ) {
1539                 $text = $this->getNumberedArgument( $name );
1540                 if ( $text === false ) {
1541                         $text = $this->getNamedArgument( $name );
1542                 }
1543                 return $text;
1544         }
1545
1546         /**
1547          * Return true if the frame is a template frame
1548          *
1549          * @return bool
1550          */
1551         function isTemplate() {
1552                 return true;
1553         }
1554 }
1555
1556 /**
1557  * Expansion frame with custom arguments
1558  * @ingroup Parser
1559  */
1560 class PPCustomFrame_DOM extends PPFrame_DOM {
1561         var $args;
1562
1563         function __construct( $preprocessor, $args ) {
1564                 parent::__construct( $preprocessor );
1565                 $this->args = $args;
1566         }
1567
1568         function __toString() {
1569                 $s = 'cstmframe{';
1570                 $first = true;
1571                 foreach ( $this->args as $name => $value ) {
1572                         if ( $first ) {
1573                                 $first = false;
1574                         } else {
1575                                 $s .= ', ';
1576                         }
1577                         $s .= "\"$name\":\"" .
1578                                 str_replace( '"', '\\"', $value->__toString() ) . '"';
1579                 }
1580                 $s .= '}';
1581                 return $s;
1582         }
1583
1584         /**
1585          * @return bool
1586          */
1587         function isEmpty() {
1588                 return !count( $this->args );
1589         }
1590
1591         function getArgument( $index ) {
1592                 if ( !isset( $this->args[$index] ) ) {
1593                         return false;
1594                 }
1595                 return $this->args[$index];
1596         }
1597
1598         function getArguments() {
1599                 return $this->args;
1600         }
1601 }
1602
1603 /**
1604  * @ingroup Parser
1605  */
1606 class PPNode_DOM implements PPNode {
1607
1608         /**
1609          * @var DOMElement
1610          */
1611         var $node;
1612         var $xpath;
1613
1614         function __construct( $node, $xpath = false ) {
1615                 $this->node = $node;
1616         }
1617
1618         /**
1619          * @return DOMXPath
1620          */
1621         function getXPath() {
1622                 if ( $this->xpath === null ) {
1623                         $this->xpath = new DOMXPath( $this->node->ownerDocument );
1624                 }
1625                 return $this->xpath;
1626         }
1627
1628         function __toString() {
1629                 if ( $this->node instanceof DOMNodeList ) {
1630                         $s = '';
1631                         foreach ( $this->node as $node ) {
1632                                 $s .= $node->ownerDocument->saveXML( $node );
1633                         }
1634                 } else {
1635                         $s = $this->node->ownerDocument->saveXML( $this->node );
1636                 }
1637                 return $s;
1638         }
1639
1640         /**
1641          * @return bool|PPNode_DOM
1642          */
1643         function getChildren() {
1644                 return $this->node->childNodes ? new self( $this->node->childNodes ) : false;
1645         }
1646
1647         /**
1648          * @return bool|PPNode_DOM
1649          */
1650         function getFirstChild() {
1651                 return $this->node->firstChild ? new self( $this->node->firstChild ) : false;
1652         }
1653
1654         /**
1655          * @return bool|PPNode_DOM
1656          */
1657         function getNextSibling() {
1658                 return $this->node->nextSibling ? new self( $this->node->nextSibling ) : false;
1659         }
1660
1661         /**
1662          * @param $type
1663          *
1664          * @return bool|PPNode_DOM
1665          */
1666         function getChildrenOfType( $type ) {
1667                 return new self( $this->getXPath()->query( $type, $this->node ) );
1668         }
1669
1670         /**
1671          * @return int
1672          */
1673         function getLength() {
1674                 if ( $this->node instanceof DOMNodeList ) {
1675                         return $this->node->length;
1676                 } else {
1677                         return false;
1678                 }
1679         }
1680
1681         /**
1682          * @param $i
1683          * @return bool|PPNode_DOM
1684          */
1685         function item( $i ) {
1686                 $item = $this->node->item( $i );
1687                 return $item ? new self( $item ) : false;
1688         }
1689
1690         /**
1691          * @return string
1692          */
1693         function getName() {
1694                 if ( $this->node instanceof DOMNodeList ) {
1695                         return '#nodelist';
1696                 } else {
1697                         return $this->node->nodeName;
1698                 }
1699         }
1700
1701         /**
1702          * Split a "<part>" node into an associative array containing:
1703          *  - name          PPNode name
1704          *  - index         String index
1705          *  - value         PPNode value
1706          *
1707          * @throws MWException
1708          * @return array
1709          */
1710         function splitArg() {
1711                 $xpath = $this->getXPath();
1712                 $names = $xpath->query( 'name', $this->node );
1713                 $values = $xpath->query( 'value', $this->node );
1714                 if ( !$names->length || !$values->length ) {
1715                         throw new MWException( 'Invalid brace node passed to ' . __METHOD__ );
1716                 }
1717                 $name = $names->item( 0 );
1718                 $index = $name->getAttribute( 'index' );
1719                 return array(
1720                         'name' => new self( $name ),
1721                         'index' => $index,
1722                         'value' => new self( $values->item( 0 ) ) );
1723         }
1724
1725         /**
1726          * Split an "<ext>" node into an associative array containing name, attr, inner and close
1727          * All values in the resulting array are PPNodes. Inner and close are optional.
1728          *
1729          * @throws MWException
1730          * @return array
1731          */
1732         function splitExt() {
1733                 $xpath = $this->getXPath();
1734                 $names = $xpath->query( 'name', $this->node );
1735                 $attrs = $xpath->query( 'attr', $this->node );
1736                 $inners = $xpath->query( 'inner', $this->node );
1737                 $closes = $xpath->query( 'close', $this->node );
1738                 if ( !$names->length || !$attrs->length ) {
1739                         throw new MWException( 'Invalid ext node passed to ' . __METHOD__ );
1740                 }
1741                 $parts = array(
1742                         'name' => new self( $names->item( 0 ) ),
1743                         'attr' => new self( $attrs->item( 0 ) ) );
1744                 if ( $inners->length ) {
1745                         $parts['inner'] = new self( $inners->item( 0 ) );
1746                 }
1747                 if ( $closes->length ) {
1748                         $parts['close'] = new self( $closes->item( 0 ) );
1749                 }
1750                 return $parts;
1751         }
1752
1753         /**
1754          * Split a "<h>" node
1755          * @throws MWException
1756          * @return array
1757          */
1758         function splitHeading() {
1759                 if ( $this->getName() !== 'h' ) {
1760                         throw new MWException( 'Invalid h node passed to ' . __METHOD__ );
1761                 }
1762                 return array(
1763                         'i' => $this->node->getAttribute( 'i' ),
1764                         'level' => $this->node->getAttribute( 'level' ),
1765                         'contents' => $this->getChildren()
1766                 );
1767         }
1768 }