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