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