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