includes/parser/Preprocessor_DOM.php

   1 <?php
   2 /**
   3  * Preprocessor using PHP's dom extension
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Parser
  22  */
  23
  24 /**
  25  * @ingroup Parser
  26  */
  27 class Preprocessor_DOM implements Preprocessor {
  28
  29         /**
  30          * @var Parser
  31          */
  32         var $parser;
  33
  34         var $memoryLimit;
  35
  36         const CACHE_VERSION = 1;
  37
  38         function __construct( $parser ) {
  39                 $this->parser = $parser;
  40                 $mem = ini_get( 'memory_limit' );
  41                 $this->memoryLimit = false;
  42                 if ( strval( $mem ) !== '' && $mem != -1 ) {
  43                         if ( preg_match( '/^\d+$/', $mem ) ) {
  44                                 $this->memoryLimit = $mem;
  45                         } elseif ( preg_match( '/^(\d+)M$/i', $mem, $m ) ) {
  46                                 $this->memoryLimit = $m[1] * 1048576;
  47                         }
  48                 }
  49         }
  50
  51         /**
  52          * @return PPFrame_DOM
  53          */
  54         function newFrame() {
  55                 return new PPFrame_DOM( $this );
  56         }
  57
  58         /**
  59          * @param $args array
  60          * @return PPCustomFrame_DOM
  61          */
  62         function newCustomFrame( $args ) {
  63                 return new PPCustomFrame_DOM( $this, $args );
  64         }
  65
  66         /**
  67          * @param $values
  68          * @return PPNode_DOM
  69          */
  70         function newPartNodeArray( $values ) {
  71                 //NOTE: DOM manipulation is slower than building & parsing XML! (or so Tim sais)
  72                 $xml = "<list>";
  73
  74                 foreach ( $values as $k => $val ) {
  75                         if ( is_int( $k ) ) {
  76                                 $xml .= "<part><name index=\"$k\"/><value>" . htmlspecialchars( $val ) . "</value></part>";
  77                         } else {
  78                                 $xml .= "<part><name>" . htmlspecialchars( $k ) . "</name>=<value>" . htmlspecialchars( $val ) . "</value></part>";
  79                         }
  80                 }
  81
  82                 $xml .= "</list>";
  83
  84                 $dom = new DOMDocument();
  85                 $dom->loadXML( $xml );
  86                 $root = $dom->documentElement;
  87
  88                 $node = new PPNode_DOM( $root->childNodes );
  89                 return $node;
  90         }
  91
  92         /**
  93          * @throws MWException
  94          * @return bool
  95          */
  96         function memCheck() {
  97                 if ( $this->memoryLimit === false ) {
  98                         return true;
  99                 }
 100                 $usage = memory_get_usage();
 101                 if ( $usage > $this->memoryLimit * 0.9 ) {
 102                         $limit = intval( $this->memoryLimit * 0.9 / 1048576 + 0.5 );
 103                         throw new MWException( "Preprocessor hit 90% memory limit ($limit MB)" );
 104                 }
 105                 return $usage <= $this->memoryLimit * 0.8;
 106         }
 107
 108         /**
 109          * Preprocess some wikitext and return the document tree.
 110          * This is the ghost of Parser::replace_variables().
 111          *
 112          * @param string $text the text to parse
 113          * @param $flags Integer: bitwise combination of:
 114          *          Parser::PTD_FOR_INCLUSION    Handle "<noinclude>" and "<includeonly>" as if the text is being
 115          *                                     included. Default is to assume a direct page view.
 116          *
 117          * The generated DOM tree must depend only on the input text and the flags.
 118          * The DOM tree must be the same in OT_HTML and OT_WIKI mode, to avoid a regression of bug 4899.
 119          *
 120          * Any flag added to the $flags parameter here, or any other parameter liable to cause a
 121          * change in the DOM tree for a given text, must be passed through the section identifier
 122          * in the section edit link and thus back to extractSections().
 123          *
 124          * The output of this function is currently only cached in process memory, but a persistent
 125          * cache may be implemented at a later date which takes further advantage of these strict
 126          * dependency requirements.
 127          *
 128          * @throws MWException
 129          * @return PPNode_DOM
 130          */
 131         function preprocessToObj( $text, $flags = 0 ) {
 132                 wfProfileIn( __METHOD__ );
 133                 global $wgMemc, $wgPreprocessorCacheThreshold;
 134
 135                 $xml = false;
 136                 $cacheable = ( $wgPreprocessorCacheThreshold !== false
 137                         && strlen( $text ) > $wgPreprocessorCacheThreshold );
 138                 if ( $cacheable ) {
 139                         wfProfileIn( __METHOD__ . '-cacheable' );
 140
 141                         $cacheKey = wfMemcKey( 'preprocess-xml', md5( $text ), $flags );
 142                         $cacheValue = $wgMemc->get( $cacheKey );
 143                         if ( $cacheValue ) {
 144                                 $version = substr( $cacheValue, 0, 8 );
 145                                 if ( intval( $version ) == self::CACHE_VERSION ) {
 146                                         $xml = substr( $cacheValue, 8 );
 147                                         // From the cache
 148                                         wfDebugLog( "Preprocessor", "Loaded preprocessor XML from memcached (key $cacheKey)" );
 149                                 }
 150                         }
 151                         if ( $xml === false ) {
 152                                 wfProfileIn( __METHOD__ . '-cache-miss' );
 153                                 $xml = $this->preprocessToXml( $text, $flags );
 154                                 $cacheValue = sprintf( "%08d", self::CACHE_VERSION ) . $xml;
 155                                 $wgMemc->set( $cacheKey, $cacheValue, 86400 );
 156                                 wfProfileOut( __METHOD__ . '-cache-miss' );
 157                                 wfDebugLog( "Preprocessor", "Saved preprocessor XML to memcached (key $cacheKey)" );
 158                         }
 159                 } else {
 160                         $xml = $this->preprocessToXml( $text, $flags );
 161                 }
 162
 163                 // Fail if the number of elements exceeds acceptable limits
 164                 // Do not attempt to generate the DOM
 165                 $this->parser->mGeneratedPPNodeCount += substr_count( $xml, '<' );
 166                 $max = $this->parser->mOptions->getMaxGeneratedPPNodeCount();
 167                 if ( $this->parser->mGeneratedPPNodeCount > $max ) {
 168                         if ( $cacheable ) {
 169                                 wfProfileOut( __METHOD__ . '-cacheable' );
 170                         }
 171                         wfProfileOut( __METHOD__ );
 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                 }
 186                 if ( $result ) {
 187                         $obj = new PPNode_DOM( $dom->documentElement );
 188                 }
 189                 wfProfileOut( __METHOD__ . '-loadXML' );
 190
 191                 if ( $cacheable ) {
 192                         wfProfileOut( __METHOD__ . '-cacheable' );
 193                 }
 194
 195                 wfProfileOut( __METHOD__ );
 196
 197                 if ( !$result ) {
 198                         throw new MWException( __METHOD__ . ' generated invalid XML' );
 199                 }
 200                 return $obj;
 201         }
 202
 203         /**
 204          * @param $text string
 205          * @param $flags int
 206          * @return string
 207          */
 208         function preprocessToXml( $text, $flags = 0 ) {
 209                 wfProfileIn( __METHOD__ );
 210                 $rules = array(
 211                         '{' => array(
 212                                 'end' => '}',
 213                                 'names' => array(
 214                                         2 => 'template',
 215                                         3 => 'tplarg',
 216                                 ),
 217                                 'min' => 2,
 218                                 'max' => 3,
 219                         ),
 220                         '[' => array(
 221                                 'end' => ']',
 222                                 'names' => array( 2 => null ),
 223                                 'min' => 2,
 224                                 'max' => 2,
 225                         )
 226                 );
 227
 228                 $forInclusion = $flags & Parser::PTD_FOR_INCLUSION;
 229
 230                 $xmlishElements = $this->parser->getStripList();
 231                 $enableOnlyinclude = false;
 232                 if ( $forInclusion ) {
 233                         $ignoredTags = array( 'includeonly', '/includeonly' );
 234                         $ignoredElements = array( 'noinclude' );
 235                         $xmlishElements[] = 'noinclude';
 236                         if ( strpos( $text, '<onlyinclude>' ) !== false && strpos( $text, '</onlyinclude>' ) !== false ) {
 237                                 $enableOnlyinclude = true;
 238                         }
 239                 } else {
 240                         $ignoredTags = array( 'noinclude', '/noinclude', 'onlyinclude', '/onlyinclude' );
 241                         $ignoredElements = array( 'includeonly' );
 242                         $xmlishElements[] = 'includeonly';
 243                 }
 244                 $xmlishRegex = implode( '|', array_merge( $xmlishElements, $ignoredTags ) );
 245
 246                 // Use "A" modifier (anchored) instead of "^", because ^ doesn't work with an offset
 247                 $elementsRegex = "~($xmlishRegex)(?:\s|\/>|>)|(!--)~iA";
 248
 249                 $stack = new PPDStack;
 250
 251                 $searchBase = "[{<\n"; #}
 252                 $revText = strrev( $text ); // For fast reverse searches
 253                 $lengthText = strlen( $text );
 254
 255                 $i = 0;                     # Input pointer, starts out pointing to a pseudo-newline before the start
 256                 $accum =& $stack->getAccum();   # Current accumulator
 257                 $accum = '<root>';
 258                 $findEquals = false;            # True to find equals signs in arguments
 259                 $findPipe = false;              # True to take notice of pipe characters
 260                 $headingIndex = 1;
 261                 $inHeading = false;        # True if $i is inside a possible heading
 262                 $noMoreGT = false;         # True if there are no more greater-than (>) signs right of $i
 263                 $findOnlyinclude = $enableOnlyinclude; # True to ignore all input up to the next <onlyinclude>
 264                 $fakeLineStart = true;     # Do a line-start run without outputting an LF character
 265
 266                 while ( true ) {
 267                         //$this->memCheck();
 268
 269                         if ( $findOnlyinclude ) {
 270                                 // Ignore all input up to the next <onlyinclude>
 271                                 $startPos = strpos( $text, '<onlyinclude>', $i );
 272                                 if ( $startPos === false ) {
 273                                         // Ignored section runs to the end
 274                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i ) ) . '</ignore>';
 275                                         break;
 276                                 }
 277                                 $tagEndPos = $startPos + strlen( '<onlyinclude>' ); // past-the-end
 278                                 $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i, $tagEndPos - $i ) ) . '</ignore>';
 279                                 $i = $tagEndPos;
 280                                 $findOnlyinclude = false;
 281                         }
 282
 283                         if ( $fakeLineStart ) {
 284                                 $found = 'line-start';
 285                                 $curChar = '';
 286                         } else {
 287                                 # Find next opening brace, closing brace or pipe
 288                                 $search = $searchBase;
 289                                 if ( $stack->top === false ) {
 290                                         $currentClosing = '';
 291                                 } else {
 292                                         $currentClosing = $stack->top->close;
 293                                         $search .= $currentClosing;
 294                                 }
 295                                 if ( $findPipe ) {
 296                                         $search .= '|';
 297                                 }
 298                                 if ( $findEquals ) {
 299                                         // First equals will be for the template
 300                                         $search .= '=';
 301                                 }
 302                                 $rule = null;
 303                                 # Output literal section, advance input counter
 304                                 $literalLength = strcspn( $text, $search, $i );
 305                                 if ( $literalLength > 0 ) {
 306                                         $accum .= htmlspecialchars( substr( $text, $i, $literalLength ) );
 307                                         $i += $literalLength;
 308                                 }
 309                                 if ( $i >= $lengthText ) {
 310                                         if ( $currentClosing == "\n" ) {
 311                                                 // Do a past-the-end run to finish off the heading
 312                                                 $curChar = '';
 313                                                 $found = 'line-end';
 314                                         } else {
 315                                                 # All done
 316                                                 break;
 317                                         }
 318                                 } else {
 319                                         $curChar = $text[$i];
 320                                         if ( $curChar == '|' ) {
 321                                                 $found = 'pipe';
 322                                         } elseif ( $curChar == '=' ) {
 323                                                 $found = 'equals';
 324                                         } elseif ( $curChar == '<' ) {
 325                                                 $found = 'angle';
 326                                         } elseif ( $curChar == "\n" ) {
 327                                                 if ( $inHeading ) {
 328                                                         $found = 'line-end';
 329                                                 } else {
 330                                                         $found = 'line-start';
 331                                                 }
 332                                         } elseif ( $curChar == $currentClosing ) {
 333                                                 $found = 'close';
 334                                         } elseif ( isset( $rules[$curChar] ) ) {
 335                                                 $found = 'open';
 336                                                 $rule = $rules[$curChar];
 337                                         } else {
 338                                                 # Some versions of PHP have a strcspn which stops on null characters
 339                                                 # Ignore and continue
 340                                                 ++$i;
 341                                                 continue;
 342                                         }
 343                                 }
 344                         }
 345
 346                         if ( $found == 'angle' ) {
 347                                 $matches = false;
 348                                 // Handle </onlyinclude>
 349                                 if ( $enableOnlyinclude && substr( $text, $i, strlen( '</onlyinclude>' ) ) == '</onlyinclude>' ) {
 350                                         $findOnlyinclude = true;
 351                                         continue;
 352                                 }
 353
 354                                 // Determine element name
 355                                 if ( !preg_match( $elementsRegex, $text, $matches, 0, $i + 1 ) ) {
 356                                         // Element name missing or not listed
 357                                         $accum .= '&lt;';
 358                                         ++$i;
 359                                         continue;
 360                                 }
 361                                 // Handle comments
 362                                 if ( isset( $matches[2] ) && $matches[2] == '!--' ) {
 363
 364                                         // To avoid leaving blank lines, when a sequence of
 365                                         // space-separated comments is both preceded and followed by
 366                                         // a newline (ignoring spaces), then
 367                                         // trim leading and trailing spaces and the trailing newline.
 368
 369                                         // Find the end
 370                                         $endPos = strpos( $text, '-->', $i + 4 );
 371                                         if ( $endPos === false ) {
 372                                                 // Unclosed comment in input, runs to end
 373                                                 $inner = substr( $text, $i );
 374                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 375                                                 $i = $lengthText;
 376                                         } else {
 377                                                 // Search backwards for leading whitespace
 378                                                 $wsStart = $i ? ( $i - strspn( $revText, " \t", $lengthText - $i ) ) : 0;
 379
 380                                                 // Search forwards for trailing whitespace
 381                                                 // $wsEnd will be the position of the last space (or the '>' if there's none)
 382                                                 $wsEnd = $endPos + 2 + strspn( $text, " \t", $endPos + 3 );
 383
 384                                                 // Keep looking forward as long as we're finding more
 385                                                 // comments.
 386                                                 $comments = array( array( $wsStart, $wsEnd ) );
 387                                                 while ( substr( $text, $wsEnd + 1, 4 ) == '<!--' ) {
 388                                                         $c = strpos( $text, '-->', $wsEnd + 4 );
 389                                                         if ( $c === false ) {
 390                                                                 break;
 391                                                         }
 392                                                         $c = $c + 2 + strspn( $text, " \t", $c + 3 );
 393                                                         $comments[] = array( $wsEnd + 1, $c );
 394                                                         $wsEnd = $c;
 395                                                 }
 396
 397                                                 // Eat the line if possible
 398                                                 // TODO: This could theoretically be done if $wsStart == 0, i.e. for comments at
 399                                                 // the overall start. That's not how Sanitizer::removeHTMLcomments() did it, but
 400                                                 // it's a possible beneficial b/c break.
 401                                                 if ( $wsStart > 0 && substr( $text, $wsStart - 1, 1 ) == "\n"
 402                                                         && substr( $text, $wsEnd + 1, 1 ) == "\n"
 403                                                 ) {
 404                                                         // Remove leading whitespace from the end of the accumulator
 405                                                         // Sanity check first though
 406                                                         $wsLength = $i - $wsStart;
 407                                                         if ( $wsLength > 0
 408                                                                 && strspn( $accum, " \t", -$wsLength ) === $wsLength
 409                                                         ) {
 410                                                                 $accum = substr( $accum, 0, -$wsLength );
 411                                                         }
 412
 413                                                         // Dump all but the last comment to the accumulator
 414                                                         foreach ( $comments as $j => $com ) {
 415                                                                 $startPos = $com[0];
 416                                                                 $endPos = $com[1] + 1;
 417                                                                 if ( $j == ( count( $comments ) - 1 ) ) {
 418                                                                         break;
 419                                                                 }
 420                                                                 $inner = substr( $text, $startPos, $endPos - $startPos );
 421                                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 422                                                         }
 423
 424                                                         // Do a line-start run next time to look for headings after the comment
 425                                                         $fakeLineStart = true;
 426                                                 } else {
 427                                                         // No line to eat, just take the comment itself
 428                                                         $startPos = $i;
 429                                                         $endPos += 2;
 430                                                 }
 431
 432                                                 if ( $stack->top ) {
 433                                                         $part = $stack->top->getCurrentPart();
 434                                                         if ( !( isset( $part->commentEnd ) && $part->commentEnd == $wsStart - 1 ) ) {
 435                                                                 $part->visualEnd = $wsStart;
 436                                                         }
 437                                                         // Else comments abutting, no change in visual end
 438                                                         $part->commentEnd = $endPos;
 439                                                 }
 440                                                 $i = $endPos + 1;
 441                                                 $inner = substr( $text, $startPos, $endPos - $startPos + 1 );
 442                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 443                                         }
 444                                         continue;
 445                                 }
 446                                 $name = $matches[1];
 447                                 $lowerName = strtolower( $name );
 448                                 $attrStart = $i + strlen( $name ) + 1;
 449
 450                                 // Find end of tag
 451                                 $tagEndPos = $noMoreGT ? false : strpos( $text, '>', $attrStart );
 452                                 if ( $tagEndPos === false ) {
 453                                         // Infinite backtrack
 454                                         // Disable tag search to prevent worst-case O(N^2) performance
 455                                         $noMoreGT = true;
 456                                         $accum .= '&lt;';
 457                                         ++$i;
 458                                         continue;
 459                                 }
 460
 461                                 // Handle ignored tags
 462                                 if ( in_array( $lowerName, $ignoredTags ) ) {
 463                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i, $tagEndPos - $i + 1 ) ) . '</ignore>';
 464                                         $i = $tagEndPos + 1;
 465                                         continue;
 466                                 }
 467
 468                                 $tagStartPos = $i;
 469                                 if ( $text[$tagEndPos - 1] == '/' ) {
 470                                         $attrEnd = $tagEndPos - 1;
 471                                         $inner = null;
 472                                         $i = $tagEndPos + 1;
 473                                         $close = '';
 474                                 } else {
 475                                         $attrEnd = $tagEndPos;
 476                                         // Find closing tag
 477                                         if ( preg_match( "/<\/" . preg_quote( $name, '/' ) . "\s*>/i",
 478                                                         $text, $matches, PREG_OFFSET_CAPTURE, $tagEndPos + 1 )
 479                                         ) {
 480                                                 $inner = substr( $text, $tagEndPos + 1, $matches[0][1] - $tagEndPos - 1 );
 481                                                 $i = $matches[0][1] + strlen( $matches[0][0] );
 482                                                 $close = '<close>' . htmlspecialchars( $matches[0][0] ) . '</close>';
 483                                         } else {
 484                                                 // No end tag -- let it run out to the end of the text.
 485                                                 $inner = substr( $text, $tagEndPos + 1 );
 486                                                 $i = $lengthText;
 487                                                 $close = '';
 488                                         }
 489                                 }
 490                                 // <includeonly> and <noinclude> just become <ignore> tags
 491                                 if ( in_array( $lowerName, $ignoredElements ) ) {
 492                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $tagStartPos, $i - $tagStartPos ) )
 493                                                 . '</ignore>';
 494                                         continue;
 495                                 }
 496
 497                                 $accum .= '<ext>';
 498                                 if ( $attrEnd <= $attrStart ) {
 499                                         $attr = '';
 500                                 } else {
 501                                         $attr = substr( $text, $attrStart, $attrEnd - $attrStart );
 502                                 }
 503                                 $accum .= '<name>' . htmlspecialchars( $name ) . '</name>' .
 504                                         // Note that the attr element contains the whitespace between name and attribute,
 505                                         // this is necessary for precise reconstruction during pre-save transform.
 506                                         '<attr>' . htmlspecialchars( $attr ) . '</attr>';
 507                                 if ( $inner !== null ) {
 508                                         $accum .= '<inner>' . htmlspecialchars( $inner ) . '</inner>';
 509                                 }
 510                                 $accum .= $close . '</ext>';
 511                         } elseif ( $found == 'line-start' ) {
 512                                 // Is this the start of a heading?
 513                                 // Line break belongs before the heading element in any case
 514                                 if ( $fakeLineStart ) {
 515                                         $fakeLineStart = false;
 516                                 } else {
 517                                         $accum .= $curChar;
 518                                         $i++;
 519                                 }
 520
 521                                 $count = strspn( $text, '=', $i, 6 );
 522                                 if ( $count == 1 && $findEquals ) {
 523                                         // DWIM: This looks kind of like a name/value separator
 524                                         // Let's let the equals handler have it and break the potential heading
 525                                         // This is heuristic, but AFAICT the methods for completely correct disambiguation are very complex.
 526                                 } elseif ( $count > 0 ) {
 527                                         $piece = array(
 528                                                 'open' => "\n",
 529                                                 'close' => "\n",
 530                                                 'parts' => array( new PPDPart( str_repeat( '=', $count ) ) ),
 531                                                 'startPos' => $i,
 532                                                 'count' => $count );
 533                                         $stack->push( $piece );
 534                                         $accum =& $stack->getAccum();
 535                                         $flags = $stack->getFlags();
 536                                         extract( $flags );
 537                                         $i += $count;
 538                                 }
 539                         } elseif ( $found == 'line-end' ) {
 540                                 $piece = $stack->top;
 541                                 // A heading must be open, otherwise \n wouldn't have been in the search list
 542                                 assert( '$piece->open == "\n"' );
 543                                 $part = $piece->getCurrentPart();
 544                                 // Search back through the input to see if it has a proper close
 545                                 // Do this using the reversed string since the other solutions (end anchor, etc.) are inefficient
 546                                 $wsLength = strspn( $revText, " \t", $lengthText - $i );
 547                                 $searchStart = $i - $wsLength;
 548                                 if ( isset( $part->commentEnd ) && $searchStart - 1 == $part->commentEnd ) {
 549                                         // Comment found at line end
 550                                         // Search for equals signs before the comment
 551                                         $searchStart = $part->visualEnd;
 552                                         $searchStart -= strspn( $revText, " \t", $lengthText - $searchStart );
 553                                 }
 554                                 $count = $piece->count;
 555                                 $equalsLength = strspn( $revText, '=', $lengthText - $searchStart );
 556                                 if ( $equalsLength > 0 ) {
 557                                         if ( $searchStart - $equalsLength == $piece->startPos ) {
 558                                                 // This is just a single string of equals signs on its own line
 559                                                 // Replicate the doHeadings behavior /={count}(.+)={count}/
 560                                                 // First find out how many equals signs there really are (don't stop at 6)
 561                                                 $count = $equalsLength;
 562                                                 if ( $count < 3 ) {
 563                                                         $count = 0;
 564                                                 } else {
 565                                                         $count = min( 6, intval( ( $count - 1 ) / 2 ) );
 566                                                 }
 567                                         } else {
 568                                                 $count = min( $equalsLength, $count );
 569                                         }
 570                                         if ( $count > 0 ) {
 571                                                 // Normal match, output <h>
 572                                                 $element = "<h level=\"$count\" i=\"$headingIndex\">$accum</h>";
 573                                                 $headingIndex++;
 574                                         } else {
 575                                                 // Single equals sign on its own line, count=0
 576                                                 $element = $accum;
 577                                         }
 578                                 } else {
 579                                         // No match, no <h>, just pass down the inner text
 580                                         $element = $accum;
 581                                 }
 582                                 // Unwind the stack
 583                                 $stack->pop();
 584                                 $accum =& $stack->getAccum();
 585                                 $flags = $stack->getFlags();
 586                                 extract( $flags );
 587
 588                                 // Append the result to the enclosing accumulator
 589                                 $accum .= $element;
 590                                 // Note that we do NOT increment the input pointer.
 591                                 // This is because the closing linebreak could be the opening linebreak of
 592                                 // another heading. Infinite loops are avoided because the next iteration MUST
 593                                 // hit the heading open case above, which unconditionally increments the
 594                                 // input pointer.
 595                         } elseif ( $found == 'open' ) {
 596                                 # count opening brace characters
 597                                 $count = strspn( $text, $curChar, $i );
 598
 599                                 # we need to add to stack only if opening brace count is enough for one of the rules
 600                                 if ( $count >= $rule['min'] ) {
 601                                         # Add it to the stack
 602                                         $piece = array(
 603                                                 'open' => $curChar,
 604                                                 'close' => $rule['end'],
 605                                                 'count' => $count,
 606                                                 'lineStart' => ( $i > 0 && $text[$i - 1] == "\n" ),
 607                                         );
 608
 609                                         $stack->push( $piece );
 610                                         $accum =& $stack->getAccum();
 611                                         $flags = $stack->getFlags();
 612                                         extract( $flags );
 613                                 } else {
 614                                         # Add literal brace(s)
 615                                         $accum .= htmlspecialchars( str_repeat( $curChar, $count ) );
 616                                 }
 617                                 $i += $count;
 618                         } elseif ( $found == 'close' ) {
 619                                 $piece = $stack->top;
 620                                 # lets check if there are enough characters for closing brace
 621                                 $maxCount = $piece->count;
 622                                 $count = strspn( $text, $curChar, $i, $maxCount );
 623
 624                                 # check for maximum matching characters (if there are 5 closing
 625                                 # characters, we will probably need only 3 - depending on the rules)
 626                                 $rule = $rules[$piece->open];
 627                                 if ( $count > $rule['max'] ) {
 628                                         # The specified maximum exists in the callback array, unless the caller
 629                                         # has made an error
 630                                         $matchingCount = $rule['max'];
 631                                 } else {
 632                                         # Count is less than the maximum
 633                                         # Skip any gaps in the callback array to find the true largest match
 634                                         # Need to use array_key_exists not isset because the callback can be null
 635                                         $matchingCount = $count;
 636                                         while ( $matchingCount > 0 && !array_key_exists( $matchingCount, $rule['names'] ) ) {
 637                                                 --$matchingCount;
 638                                         }
 639                                 }
 640
 641                                 if ( $matchingCount <= 0 ) {
 642                                         # No matching element found in callback array
 643                                         # Output a literal closing brace and continue
 644                                         $accum .= htmlspecialchars( str_repeat( $curChar, $count ) );
 645                                         $i += $count;
 646                                         continue;
 647                                 }
 648                                 $name = $rule['names'][$matchingCount];
 649                                 if ( $name === null ) {
 650                                         // No element, just literal text
 651                                         $element = $piece->breakSyntax( $matchingCount ) . str_repeat( $rule['end'], $matchingCount );
 652                                 } else {
 653                                         # Create XML element
 654                                         # Note: $parts is already XML, does not need to be encoded further
 655                                         $parts = $piece->parts;
 656                                         $title = $parts[0]->out;
 657                                         unset( $parts[0] );
 658
 659                                         # The invocation is at the start of the line if lineStart is set in
 660                                         # the stack, and all opening brackets are used up.
 661                                         if ( $maxCount == $matchingCount && !empty( $piece->lineStart ) ) {
 662                                                 $attr = ' lineStart="1"';
 663                                         } else {
 664                                                 $attr = '';
 665                                         }
 666
 667                                         $element = "<$name$attr>";
 668                                         $element .= "<title>$title</title>";
 669                                         $argIndex = 1;
 670                                         foreach ( $parts as $part ) {
 671                                                 if ( isset( $part->eqpos ) ) {
 672                                                         $argName = substr( $part->out, 0, $part->eqpos );
 673                                                         $argValue = substr( $part->out, $part->eqpos + 1 );
 674                                                         $element .= "<part><name>$argName</name>=<value>$argValue</value></part>";
 675                                                 } else {
 676                                                         $element .= "<part><name index=\"$argIndex\" /><value>{$part->out}</value></part>";
 677                                                         $argIndex++;
 678                                                 }
 679                                         }
 680                                         $element .= "</$name>";
 681                                 }
 682
 683                                 # Advance input pointer
 684                                 $i += $matchingCount;
 685
 686                                 # Unwind the stack
 687                                 $stack->pop();
 688                                 $accum =& $stack->getAccum();
 689
 690                                 # Re-add the old stack element if it still has unmatched opening characters remaining
 691                                 if ( $matchingCount < $piece->count ) {
 692                                         $piece->parts = array( new PPDPart );
 693                                         $piece->count -= $matchingCount;
 694                                         # do we still qualify for any callback with remaining count?
 695                                         $min = $rules[$piece->open]['min'];
 696                                         if ( $piece->count >= $min ) {
 697                                                 $stack->push( $piece );
 698                                                 $accum =& $stack->getAccum();
 699                                         } else {
 700                                                 $accum .= str_repeat( $piece->open, $piece->count );
 701                                         }
 702                                 }
 703                                 $flags = $stack->getFlags();
 704                                 extract( $flags );
 705
 706                                 # Add XML element to the enclosing accumulator
 707                                 $accum .= $element;
 708                         } elseif ( $found == 'pipe' ) {
 709                                 $findEquals = true; // shortcut for getFlags()
 710                                 $stack->addPart();
 711                                 $accum =& $stack->getAccum();
 712                                 ++$i;
 713                         } elseif ( $found == 'equals' ) {
 714                                 $findEquals = false; // shortcut for getFlags()
 715                                 $stack->getCurrentPart()->eqpos = strlen( $accum );
 716                                 $accum .= '=';
 717                                 ++$i;
 718                         }
 719                 }
 720
 721                 # Output any remaining unclosed brackets
 722                 foreach ( $stack->stack as $piece ) {
 723                         $stack->rootAccum .= $piece->breakSyntax();
 724                 }
 725                 $stack->rootAccum .= '</root>';
 726                 $xml = $stack->rootAccum;
 727
 728                 wfProfileOut( __METHOD__ );
 729
 730                 return $xml;
 731         }
 732 }
 733
 734 /**
 735  * Stack class to help Preprocessor::preprocessToObj()
 736  * @ingroup Parser
 737  */
 738 class PPDStack {
 739         var $stack, $rootAccum;
 740
 741         /**
 742          * @var PPDStack
 743          */
 744         var $top;
 745         var $out;
 746         var $elementClass = 'PPDStackElement';
 747
 748         static $false = false;
 749
 750         function __construct() {
 751                 $this->stack = array();
 752                 $this->top = false;
 753                 $this->rootAccum = '';
 754                 $this->accum =& $this->rootAccum;
 755         }
 756
 757         /**
 758          * @return int
 759          */
 760         function count() {
 761                 return count( $this->stack );
 762         }
 763
 764         function &getAccum() {
 765                 return $this->accum;
 766         }
 767
 768         function getCurrentPart() {
 769                 if ( $this->top === false ) {
 770                         return false;
 771                 } else {
 772                         return $this->top->getCurrentPart();
 773                 }
 774         }
 775
 776         function push( $data ) {
 777                 if ( $data instanceof $this->elementClass ) {
 778                         $this->stack[] = $data;
 779                 } else {
 780                         $class = $this->elementClass;
 781                         $this->stack[] = new $class( $data );
 782                 }
 783                 $this->top = $this->stack[count( $this->stack ) - 1];
 784                 $this->accum =& $this->top->getAccum();
 785         }
 786
 787         function pop() {
 788                 if ( !count( $this->stack ) ) {
 789                         throw new MWException( __METHOD__ . ': no elements remaining' );
 790                 }
 791                 $temp = array_pop( $this->stack );
 792
 793                 if ( count( $this->stack ) ) {
 794                         $this->top = $this->stack[count( $this->stack ) - 1];
 795                         $this->accum =& $this->top->getAccum();
 796                 } else {
 797                         $this->top = self::$false;
 798                         $this->accum =& $this->rootAccum;
 799                 }
 800                 return $temp;
 801         }
 802
 803         function addPart( $s = '' ) {
 804                 $this->top->addPart( $s );
 805                 $this->accum =& $this->top->getAccum();
 806         }
 807
 808         /**
 809          * @return array
 810          */
 811         function getFlags() {
 812                 if ( !count( $this->stack ) ) {
 813                         return array(
 814                                 'findEquals' => false,
 815                                 'findPipe' => false,
 816                                 'inHeading' => false,
 817                         );
 818                 } else {
 819                         return $this->top->getFlags();
 820                 }
 821         }
 822 }
 823
 824 /**
 825  * @ingroup Parser
 826  */
 827 class PPDStackElement {
 828         var     $open,              // Opening character (\n for heading)
 829                 $close,             // Matching closing character
 830                 $count,             // Number of opening characters found (number of "=" for heading)
 831                 $parts,             // Array of PPDPart objects describing pipe-separated parts.
 832                 $lineStart;         // True if the open char appeared at the start of the input line. Not set for headings.
 833
 834         var $partClass = 'PPDPart';
 835
 836         function __construct( $data = array() ) {
 837                 $class = $this->partClass;
 838                 $this->parts = array( new $class );
 839
 840                 foreach ( $data as $name => $value ) {
 841                         $this->$name = $value;
 842                 }
 843         }
 844
 845         function &getAccum() {
 846                 return $this->parts[count( $this->parts ) - 1]->out;
 847         }
 848
 849         function addPart( $s = '' ) {
 850                 $class = $this->partClass;
 851                 $this->parts[] = new $class( $s );
 852         }
 853
 854         function getCurrentPart() {
 855                 return $this->parts[count( $this->parts ) - 1];
 856         }
 857
 858         /**
 859          * @return array
 860          */
 861         function getFlags() {
 862                 $partCount = count( $this->parts );
 863                 $findPipe = $this->open != "\n" && $this->open != '[';
 864                 return array(
 865                         'findPipe' => $findPipe,
 866                         'findEquals' => $findPipe && $partCount > 1 && !isset( $this->parts[$partCount - 1]->eqpos ),
 867                         'inHeading' => $this->open == "\n",
 868                 );
 869         }
 870
 871         /**
 872          * Get the output string that would result if the close is not found.
 873          *
 874          * @return string
 875          */
 876         function breakSyntax( $openingCount = false ) {
 877                 if ( $this->open == "\n" ) {
 878                         $s = $this->parts[0]->out;
 879                 } else {
 880                         if ( $openingCount === false ) {
 881                                 $openingCount = $this->count;
 882                         }
 883                         $s = str_repeat( $this->open, $openingCount );
 884                         $first = true;
 885                         foreach ( $this->parts as $part ) {
 886                                 if ( $first ) {
 887                                         $first = false;
 888                                 } else {
 889                                         $s .= '|';
 890                                 }
 891                                 $s .= $part->out;
 892                         }
 893                 }
 894                 return $s;
 895         }
 896 }
 897
 898 /**
 899  * @ingroup Parser
 900  */
 901 class PPDPart {
 902         var $out; // Output accumulator string
 903
 904         // Optional member variables:
 905         //   eqpos        Position of equals sign in output accumulator
 906         //   commentEnd   Past-the-end input pointer for the last comment encountered
 907         //   visualEnd    Past-the-end input pointer for the end of the accumulator minus comments
 908
 909         function __construct( $out = '' ) {
 910                 $this->out = $out;
 911         }
 912 }
 913
 914 /**
 915  * An expansion frame, used as a context to expand the result of preprocessToObj()
 916  * @ingroup Parser
 917  */
 918 class PPFrame_DOM implements PPFrame {
 919
 920         /**
 921          * @var Preprocessor
 922          */
 923         var $preprocessor;
 924
 925         /**
 926          * @var Parser
 927          */
 928         var $parser;
 929
 930         /**
 931          * @var Title
 932          */
 933         var $title;
 934         var $titleCache;
 935
 936         /**
 937          * Hashtable listing templates which are disallowed for expansion in this frame,
 938          * having been encountered previously in parent frames.
 939          */
 940         var $loopCheckHash;
 941
 942         /**
 943          * Recursion depth of this frame, top = 0
 944          * Note that this is NOT the same as expansion depth in expand()
 945          */
 946         var $depth;
 947
 948         /**
 949          * Construct a new preprocessor frame.
 950          * @param $preprocessor Preprocessor The parent preprocessor
 951          */
 952         function __construct( $preprocessor ) {
 953                 $this->preprocessor = $preprocessor;
 954                 $this->parser = $preprocessor->parser;
 955                 $this->title = $this->parser->mTitle;
 956                 $this->titleCache = array( $this->title ? $this->title->getPrefixedDBkey() : false );
 957                 $this->loopCheckHash = array();
 958                 $this->depth = 0;
 959         }
 960
 961         /**
 962          * Create a new child frame
 963          * $args is optionally a multi-root PPNode or array containing the template arguments
 964          *
 965          * @return PPTemplateFrame_DOM
 966          */
 967         function newChild( $args = false, $title = false, $indexOffset = 0 ) {
 968                 $namedArgs = array();
 969                 $numberedArgs = array();
 970                 if ( $title === false ) {
 971                         $title = $this->title;
 972                 }
 973                 if ( $args !== false ) {
 974                         $xpath = false;
 975                         if ( $args instanceof PPNode ) {
 976                                 $args = $args->node;
 977                         }
 978                         foreach ( $args as $arg ) {
 979                                 if ( $arg instanceof PPNode ) {
 980                                         $arg = $arg->node;
 981                                 }
 982                                 if ( !$xpath ) {
 983                                         $xpath = new DOMXPath( $arg->ownerDocument );
 984                                 }
 985
 986                                 $nameNodes = $xpath->query( 'name', $arg );
 987                                 $value = $xpath->query( 'value', $arg );
 988                                 if ( $nameNodes->item( 0 )->hasAttributes() ) {
 989                                         // Numbered parameter
 990                                         $index = $nameNodes->item( 0 )->attributes->getNamedItem( 'index' )->textContent;
 991                                         $index = $index - $indexOffset;
 992                                         $numberedArgs[$index] = $value->item( 0 );
 993                                         unset( $namedArgs[$index] );
 994                                 } else {
 995                                         // Named parameter
 996                                         $name = trim( $this->expand( $nameNodes->item( 0 ), PPFrame::STRIP_COMMENTS ) );
 997                                         $namedArgs[$name] = $value->item( 0 );
 998                                         unset( $numberedArgs[$name] );
 999                                 }
1000                         }
1001                 }
1002                 return new PPTemplateFrame_DOM( $this->preprocessor, $this, $numberedArgs, $namedArgs, $title );
1003         }
1004
1005         /**
1006          * @throws MWException
1007          * @param $root
1008          * @param $flags int
1009          * @return string
1010          */
1011         function expand( $root, $flags = 0 ) {
1012                 static $expansionDepth = 0;
1013                 if ( is_string( $root ) ) {
1014                         return $root;
1015                 }
1016
1017                 if ( ++$this->parser->mPPNodeCount > $this->parser->mOptions->getMaxPPNodeCount() ) {
1018                         $this->parser->limitationWarn( 'node-count-exceeded',
1019                                 $this->parser->mPPNodeCount,
1020                                 $this->parser->mOptions->getMaxPPNodeCount()
1021                         );
1022                         return '<span class="error">Node-count limit exceeded</span>';
1023                 }
1024
1025                 if ( $expansionDepth > $this->parser->mOptions->getMaxPPExpandDepth() ) {
1026                         $this->parser->limitationWarn( 'expansion-depth-exceeded',
1027                                 $expansionDepth,
1028                                 $this->parser->mOptions->getMaxPPExpandDepth()
1029                         );
1030                         return '<span class="error">Expansion depth limit exceeded</span>';
1031                 }
1032                 wfProfileIn( __METHOD__ );
1033                 ++$expansionDepth;
1034                 if ( $expansionDepth > $this->parser->mHighestExpansionDepth ) {
1035                         $this->parser->mHighestExpansionDepth = $expansionDepth;
1036                 }
1037
1038                 if ( $root instanceof PPNode_DOM ) {
1039                         $root = $root->node;
1040                 }
1041                 if ( $root instanceof DOMDocument ) {
1042                         $root = $root->documentElement;
1043                 }
1044
1045                 $outStack = array( '', '' );
1046                 $iteratorStack = array( false, $root );
1047                 $indexStack = array( 0, 0 );
1048
1049                 while ( count( $iteratorStack ) > 1 ) {
1050                         $level = count( $outStack ) - 1;
1051                         $iteratorNode =& $iteratorStack[$level];
1052                         $out =& $outStack[$level];
1053                         $index =& $indexStack[$level];
1054
1055                         if ( $iteratorNode instanceof PPNode_DOM ) {
1056                                 $iteratorNode = $iteratorNode->node;
1057                         }
1058
1059                         if ( is_array( $iteratorNode ) ) {
1060                                 if ( $index >= count( $iteratorNode ) ) {
1061                                         // All done with this iterator
1062                                         $iteratorStack[$level] = false;
1063                                         $contextNode = false;
1064                                 } else {
1065                                         $contextNode = $iteratorNode[$index];
1066                                         $index++;
1067                                 }
1068                         } elseif ( $iteratorNode instanceof DOMNodeList ) {
1069                                 if ( $index >= $iteratorNode->length ) {
1070                                         // All done with this iterator
1071                                         $iteratorStack[$level] = false;
1072                                         $contextNode = false;
1073                                 } else {
1074                                         $contextNode = $iteratorNode->item( $index );
1075                                         $index++;
1076                                 }
1077                         } else {
1078                                 // Copy to $contextNode and then delete from iterator stack,
1079                                 // because this is not an iterator but we do have to execute it once
1080                                 $contextNode = $iteratorStack[$level];
1081                                 $iteratorStack[$level] = false;
1082                         }
1083
1084                         if ( $contextNode instanceof PPNode_DOM ) {
1085                                 $contextNode = $contextNode->node;
1086                         }
1087
1088                         $newIterator = false;
1089
1090                         if ( $contextNode === false ) {
1091                                 // nothing to do
1092                         } elseif ( is_string( $contextNode ) ) {
1093                                 $out .= $contextNode;
1094                         } elseif ( is_array( $contextNode ) || $contextNode instanceof DOMNodeList ) {
1095                                 $newIterator = $contextNode;
1096                         } elseif ( $contextNode instanceof DOMNode ) {
1097                                 if ( $contextNode->nodeType == XML_TEXT_NODE ) {
1098                                         $out .= $contextNode->nodeValue;
1099                                 } elseif ( $contextNode->nodeName == 'template' ) {
1100                                         # Double-brace expansion
1101                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1102                                         $titles = $xpath->query( 'title', $contextNode );
1103                                         $title = $titles->item( 0 );
1104                                         $parts = $xpath->query( 'part', $contextNode );
1105                                         if ( $flags & PPFrame::NO_TEMPLATES ) {
1106                                                 $newIterator = $this->virtualBracketedImplode( '{{', '|', '}}', $title, $parts );
1107                                         } else {
1108                                                 $lineStart = $contextNode->getAttribute( 'lineStart' );
1109                                                 $params = array(
1110                                                         'title' => new PPNode_DOM( $title ),
1111                                                         'parts' => new PPNode_DOM( $parts ),
1112                                                         'lineStart' => $lineStart );
1113                                                 $ret = $this->parser->braceSubstitution( $params, $this );
1114                                                 if ( isset( $ret['object'] ) ) {
1115                                                         $newIterator = $ret['object'];
1116                                                 } else {
1117                                                         $out .= $ret['text'];
1118                                                 }
1119                                         }
1120                                 } elseif ( $contextNode->nodeName == 'tplarg' ) {
1121                                         # Triple-brace expansion
1122                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1123                                         $titles = $xpath->query( 'title', $contextNode );
1124                                         $title = $titles->item( 0 );
1125                                         $parts = $xpath->query( 'part', $contextNode );
1126                                         if ( $flags & PPFrame::NO_ARGS ) {
1127                                                 $newIterator = $this->virtualBracketedImplode( '{{{', '|', '}}}', $title, $parts );
1128                                         } else {
1129                                                 $params = array(
1130                                                         'title' => new PPNode_DOM( $title ),
1131                                                         'parts' => new PPNode_DOM( $parts ) );
1132                                                 $ret = $this->parser->argSubstitution( $params, $this );
1133                                                 if ( isset( $ret['object'] ) ) {
1134                                                         $newIterator = $ret['object'];
1135                                                 } else {
1136                                                         $out .= $ret['text'];
1137                                                 }
1138                                         }
1139                                 } elseif ( $contextNode->nodeName == 'comment' ) {
1140                                         # HTML-style comment
1141                                         # Remove it in HTML, pre+remove and STRIP_COMMENTS modes
1142                                         if ( $this->parser->ot['html']
1143                                                 || ( $this->parser->ot['pre'] && $this->parser->mOptions->getRemoveComments() )
1144                                                 || ( $flags & PPFrame::STRIP_COMMENTS )
1145                                         ) {
1146                                                 $out .= '';
1147                                         }
1148                                         # Add a strip marker in PST mode so that pstPass2() can run some old-fashioned regexes on the result
1149                                         # Not in RECOVER_COMMENTS mode (extractSections) though
1150                                         elseif ( $this->parser->ot['wiki'] && !( $flags & PPFrame::RECOVER_COMMENTS ) ) {
1151                                                 $out .= $this->parser->insertStripItem( $contextNode->textContent );
1152                                         }
1153                                         # Recover the literal comment in RECOVER_COMMENTS and pre+no-remove
1154                                         else {
1155                                                 $out .= $contextNode->textContent;
1156                                         }
1157                                 } elseif ( $contextNode->nodeName == 'ignore' ) {
1158                                         # Output suppression used by <includeonly> etc.
1159                                         # OT_WIKI will only respect <ignore> in substed templates.
1160                                         # The other output types respect it unless NO_IGNORE is set.
1161                                         # extractSections() sets NO_IGNORE and so never respects it.
1162                                         if ( ( !isset( $this->parent ) && $this->parser->ot['wiki'] ) || ( $flags & PPFrame::NO_IGNORE ) ) {
1163                                                 $out .= $contextNode->textContent;
1164                                         } else {
1165                                                 $out .= '';
1166                                         }
1167                                 } elseif ( $contextNode->nodeName == 'ext' ) {
1168                                         # Extension tag
1169                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1170                                         $names = $xpath->query( 'name', $contextNode );
1171                                         $attrs = $xpath->query( 'attr', $contextNode );
1172                                         $inners = $xpath->query( 'inner', $contextNode );
1173                                         $closes = $xpath->query( 'close', $contextNode );
1174                                         $params = array(
1175                                                 'name' => new PPNode_DOM( $names->item( 0 ) ),
1176                                                 'attr' => $attrs->length > 0 ? new PPNode_DOM( $attrs->item( 0 ) ) : null,
1177                                                 'inner' => $inners->length > 0 ? new PPNode_DOM( $inners->item( 0 ) ) : null,
1178                                                 'close' => $closes->length > 0 ? new PPNode_DOM( $closes->item( 0 ) ) : null,
1179                                         );
1180                                         $out .= $this->parser->extensionSubstitution( $params, $this );
1181                                 } elseif ( $contextNode->nodeName == 'h' ) {
1182                                         # Heading
1183                                         $s = $this->expand( $contextNode->childNodes, $flags );
1184
1185                                         # Insert a heading marker only for <h> children of <root>
1186                                         # This is to stop extractSections from going over multiple tree levels
1187                                         if ( $contextNode->parentNode->nodeName == 'root' && $this->parser->ot['html'] ) {
1188                                                 # Insert heading index marker
1189                                                 $headingIndex = $contextNode->getAttribute( 'i' );
1190                                                 $titleText = $this->title->getPrefixedDBkey();
1191                                                 $this->parser->mHeadings[] = array( $titleText, $headingIndex );
1192                                                 $serial = count( $this->parser->mHeadings ) - 1;
1193                                                 $marker = "{$this->parser->mUniqPrefix}-h-$serial-" . Parser::MARKER_SUFFIX;
1194                                                 $count = $contextNode->getAttribute( 'level' );
1195                                                 $s = substr( $s, 0, $count ) . $marker . substr( $s, $count );
1196                                                 $this->parser->mStripState->addGeneral( $marker, '' );
1197                                         }
1198                                         $out .= $s;
1199                                 } else {
1200                                         # Generic recursive expansion
1201                                         $newIterator = $contextNode->childNodes;
1202                                 }
1203                         } else {
1204                                 wfProfileOut( __METHOD__ );
1205                                 throw new MWException( __METHOD__ . ': Invalid parameter type' );
1206                         }
1207
1208                         if ( $newIterator !== false ) {
1209                                 if ( $newIterator instanceof PPNode_DOM ) {
1210                                         $newIterator = $newIterator->node;
1211                                 }
1212                                 $outStack[] = '';
1213                                 $iteratorStack[] = $newIterator;
1214                                 $indexStack[] = 0;
1215                         } elseif ( $iteratorStack[$level] === false ) {
1216                                 // Return accumulated value to parent
1217                                 // With tail recursion
1218                                 while ( $iteratorStack[$level] === false && $level > 0 ) {
1219                                         $outStack[$level - 1] .= $out;
1220                                         array_pop( $outStack );
1221                                         array_pop( $iteratorStack );
1222                                         array_pop( $indexStack );
1223                                         $level--;
1224                                 }
1225                         }
1226                 }
1227                 --$expansionDepth;
1228                 wfProfileOut( __METHOD__ );
1229                 return $outStack[0];
1230         }
1231
1232         /**
1233          * @param $sep
1234          * @param $flags
1235          * @return string
1236          */
1237         function implodeWithFlags( $sep, $flags /*, ... */ ) {
1238                 $args = array_slice( func_get_args(), 2 );
1239
1240                 $first = true;
1241                 $s = '';
1242                 foreach ( $args as $root ) {
1243                         if ( $root instanceof PPNode_DOM ) {
1244                                 $root = $root->node;
1245                         }
1246                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1247                                 $root = array( $root );
1248                         }
1249                         foreach ( $root as $node ) {
1250                                 if ( $first ) {
1251                                         $first = false;
1252                                 } else {
1253                                         $s .= $sep;
1254                                 }
1255                                 $s .= $this->expand( $node, $flags );
1256                         }
1257                 }
1258                 return $s;
1259         }
1260
1261         /**
1262          * Implode with no flags specified
1263          * This previously called implodeWithFlags but has now been inlined to reduce stack depth
1264          *
1265          * @return string
1266          */
1267         function implode( $sep /*, ... */ ) {
1268                 $args = array_slice( func_get_args(), 1 );
1269
1270                 $first = true;
1271                 $s = '';
1272                 foreach ( $args as $root ) {
1273                         if ( $root instanceof PPNode_DOM ) {
1274                                 $root = $root->node;
1275                         }
1276                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1277                                 $root = array( $root );
1278                         }
1279                         foreach ( $root as $node ) {
1280                                 if ( $first ) {
1281                                         $first = false;
1282                                 } else {
1283                                         $s .= $sep;
1284                                 }
1285                                 $s .= $this->expand( $node );
1286                         }
1287                 }
1288                 return $s;
1289         }
1290
1291         /**
1292          * Makes an object that, when expand()ed, will be the same as one obtained
1293          * with implode()
1294          *
1295          * @return array
1296          */
1297         function virtualImplode( $sep /*, ... */ ) {
1298                 $args = array_slice( func_get_args(), 1 );
1299                 $out = array();
1300                 $first = true;
1301
1302                 foreach ( $args as $root ) {
1303                         if ( $root instanceof PPNode_DOM ) {
1304                                 $root = $root->node;
1305                         }
1306                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1307                                 $root = array( $root );
1308                         }
1309                         foreach ( $root as $node ) {
1310                                 if ( $first ) {
1311                                         $first = false;
1312                                 } else {
1313                                         $out[] = $sep;
1314                                 }
1315                                 $out[] = $node;
1316                         }
1317                 }
1318                 return $out;
1319         }
1320
1321         /**
1322          * Virtual implode with brackets
1323          * @return array
1324          */
1325         function virtualBracketedImplode( $start, $sep, $end /*, ... */ ) {
1326                 $args = array_slice( func_get_args(), 3 );
1327                 $out = array( $start );
1328                 $first = true;
1329
1330                 foreach ( $args as $root ) {
1331                         if ( $root instanceof PPNode_DOM ) {
1332                                 $root = $root->node;
1333                         }
1334                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1335                                 $root = array( $root );
1336                         }
1337                         foreach ( $root as $node ) {
1338                                 if ( $first ) {
1339                                         $first = false;
1340                                 } else {
1341                                         $out[] = $sep;
1342                                 }
1343                                 $out[] = $node;
1344                         }
1345                 }
1346                 $out[] = $end;
1347                 return $out;
1348         }
1349
1350         function __toString() {
1351                 return 'frame{}';
1352         }
1353
1354         function getPDBK( $level = false ) {
1355                 if ( $level === false ) {
1356                         return $this->title->getPrefixedDBkey();
1357                 } else {
1358                         return isset( $this->titleCache[$level] ) ? $this->titleCache[$level] : false;
1359                 }
1360         }
1361
1362         /**
1363          * @return array
1364          */
1365         function getArguments() {
1366                 return array();
1367         }
1368
1369         /**
1370          * @return array
1371          */
1372         function getNumberedArguments() {
1373                 return array();
1374         }
1375
1376         /**
1377          * @return array
1378          */
1379         function getNamedArguments() {
1380                 return array();
1381         }
1382
1383         /**
1384          * Returns true if there are no arguments in this frame
1385          *
1386          * @return bool
1387          */
1388         function isEmpty() {
1389                 return true;
1390         }
1391
1392         function getArgument( $name ) {
1393                 return false;
1394         }
1395
1396         /**
1397          * Returns true if the infinite loop check is OK, false if a loop is detected
1398          *
1399          * @return bool
1400          */
1401         function loopCheck( $title ) {
1402                 return !isset( $this->loopCheckHash[$title->getPrefixedDBkey()] );
1403         }
1404
1405         /**
1406          * Return true if the frame is a template frame
1407          *
1408          * @return bool
1409          */
1410         function isTemplate() {
1411                 return false;
1412         }
1413
1414         /**
1415          * Get a title of frame
1416          *
1417          * @return Title
1418          */
1419         function getTitle() {
1420                 return $this->title;
1421         }
1422 }
1423
1424 /**
1425  * Expansion frame with template arguments
1426  * @ingroup Parser
1427  */
1428 class PPTemplateFrame_DOM extends PPFrame_DOM {
1429         var $numberedArgs, $namedArgs;
1430
1431         /**
1432          * @var PPFrame_DOM
1433          */
1434         var $parent;
1435         var $numberedExpansionCache, $namedExpansionCache;
1436
1437         /**
1438          * @param $preprocessor
1439          * @param $parent PPFrame_DOM
1440          * @param $numberedArgs array
1441          * @param $namedArgs array
1442          * @param $title Title
1443          */
1444         function __construct( $preprocessor, $parent = false, $numberedArgs = array(), $namedArgs = array(), $title = false ) {
1445                 parent::__construct( $preprocessor );
1446
1447                 $this->parent = $parent;
1448                 $this->numberedArgs = $numberedArgs;
1449                 $this->namedArgs = $namedArgs;
1450                 $this->title = $title;
1451                 $pdbk = $title ? $title->getPrefixedDBkey() : false;
1452                 $this->titleCache = $parent->titleCache;
1453                 $this->titleCache[] = $pdbk;
1454                 $this->loopCheckHash = /*clone*/ $parent->loopCheckHash;
1455                 if ( $pdbk !== false ) {
1456                         $this->loopCheckHash[$pdbk] = true;
1457                 }
1458                 $this->depth = $parent->depth + 1;
1459                 $this->numberedExpansionCache = $this->namedExpansionCache = array();
1460         }
1461
1462         function __toString() {
1463                 $s = 'tplframe{';
1464                 $first = true;
1465                 $args = $this->numberedArgs + $this->namedArgs;
1466                 foreach ( $args as $name => $value ) {
1467                         if ( $first ) {
1468                                 $first = false;
1469                         } else {
1470                                 $s .= ', ';
1471                         }
1472                         $s .= "\"$name\":\"" .
1473                                 str_replace( '"', '\\"', $value->ownerDocument->saveXML( $value ) ) . '"';
1474                 }
1475                 $s .= '}';
1476                 return $s;
1477         }
1478
1479         /**
1480          * Returns true if there are no arguments in this frame
1481          *
1482          * @return bool
1483          */
1484         function isEmpty() {
1485                 return !count( $this->numberedArgs ) && !count( $this->namedArgs );
1486         }
1487
1488         function getArguments() {
1489                 $arguments = array();
1490                 foreach ( array_merge(
1491                                 array_keys( $this->numberedArgs ),
1492                                 array_keys( $this->namedArgs ) ) as $key ) {
1493                         $arguments[$key] = $this->getArgument( $key );
1494                 }
1495                 return $arguments;
1496         }
1497
1498         function getNumberedArguments() {
1499                 $arguments = array();
1500                 foreach ( array_keys( $this->numberedArgs ) as $key ) {
1501                         $arguments[$key] = $this->getArgument( $key );
1502                 }
1503                 return $arguments;
1504         }
1505
1506         function getNamedArguments() {
1507                 $arguments = array();
1508                 foreach ( array_keys( $this->namedArgs ) as $key ) {
1509                         $arguments[$key] = $this->getArgument( $key );
1510                 }
1511                 return $arguments;
1512         }
1513
1514         function getNumberedArgument( $index ) {
1515                 if ( !isset( $this->numberedArgs[$index] ) ) {
1516                         return false;
1517                 }
1518                 if ( !isset( $this->numberedExpansionCache[$index] ) ) {
1519                         # No trimming for unnamed arguments
1520                         $this->numberedExpansionCache[$index] = $this->parent->expand( $this->numberedArgs[$index], PPFrame::STRIP_COMMENTS );
1521                 }
1522                 return $this->numberedExpansionCache[$index];
1523         }
1524
1525         function getNamedArgument( $name ) {
1526                 if ( !isset( $this->namedArgs[$name] ) ) {
1527                         return false;
1528                 }
1529                 if ( !isset( $this->namedExpansionCache[$name] ) ) {
1530                         # Trim named arguments post-expand, for backwards compatibility
1531                         $this->namedExpansionCache[$name] = trim(
1532                                 $this->parent->expand( $this->namedArgs[$name], PPFrame::STRIP_COMMENTS ) );
1533                 }
1534                 return $this->namedExpansionCache[$name];
1535         }
1536
1537         function getArgument( $name ) {
1538                 $text = $this->getNumberedArgument( $name );
1539                 if ( $text === false ) {
1540                         $text = $this->getNamedArgument( $name );
1541                 }
1542                 return $text;
1543         }
1544
1545         /**
1546          * Return true if the frame is a template frame
1547          *
1548          * @return bool
1549          */
1550         function isTemplate() {
1551                 return true;
1552         }
1553 }
1554
1555 /**
1556  * Expansion frame with custom arguments
1557  * @ingroup Parser
1558  */
1559 class PPCustomFrame_DOM extends PPFrame_DOM {
1560         var $args;
1561
1562         function __construct( $preprocessor, $args ) {
1563                 parent::__construct( $preprocessor );
1564                 $this->args = $args;
1565         }
1566
1567         function __toString() {
1568                 $s = 'cstmframe{';
1569                 $first = true;
1570                 foreach ( $this->args as $name => $value ) {
1571                         if ( $first ) {
1572                                 $first = false;
1573                         } else {
1574                                 $s .= ', ';
1575                         }
1576                         $s .= "\"$name\":\"" .
1577                                 str_replace( '"', '\\"', $value->__toString() ) . '"';
1578                 }
1579                 $s .= '}';
1580                 return $s;
1581         }
1582
1583         /**
1584          * @return bool
1585          */
1586         function isEmpty() {
1587                 return !count( $this->args );
1588         }
1589
1590         function getArgument( $index ) {
1591                 if ( !isset( $this->args[$index] ) ) {
1592                         return false;
1593                 }
1594                 return $this->args[$index];
1595         }
1596
1597         function getArguments() {
1598                 return $this->args;
1599         }
1600 }
1601
1602 /**
1603  * @ingroup Parser
1604  */
1605 class PPNode_DOM implements PPNode {
1606
1607         /**
1608          * @var DOMElement
1609          */
1610         var $node;
1611         var $xpath;
1612
1613         function __construct( $node, $xpath = false ) {
1614                 $this->node = $node;
1615         }
1616
1617         /**
1618          * @return DOMXPath
1619          */
1620         function getXPath() {
1621                 if ( $this->xpath === null ) {
1622                         $this->xpath = new DOMXPath( $this->node->ownerDocument );
1623                 }
1624                 return $this->xpath;
1625         }
1626
1627         function __toString() {
1628                 if ( $this->node instanceof DOMNodeList ) {
1629                         $s = '';
1630                         foreach ( $this->node as $node ) {
1631                                 $s .= $node->ownerDocument->saveXML( $node );
1632                         }
1633                 } else {
1634                         $s = $this->node->ownerDocument->saveXML( $this->node );
1635                 }
1636                 return $s;
1637         }
1638
1639         /**
1640          * @return bool|PPNode_DOM
1641          */
1642         function getChildren() {
1643                 return $this->node->childNodes ? new self( $this->node->childNodes ) : false;
1644         }
1645
1646         /**
1647          * @return bool|PPNode_DOM
1648          */
1649         function getFirstChild() {
1650                 return $this->node->firstChild ? new self( $this->node->firstChild ) : false;
1651         }
1652
1653         /**
1654          * @return bool|PPNode_DOM
1655          */
1656         function getNextSibling() {
1657                 return $this->node->nextSibling ? new self( $this->node->nextSibling ) : false;
1658         }
1659
1660         /**
1661          * @param $type
1662          *
1663          * @return bool|PPNode_DOM
1664          */
1665         function getChildrenOfType( $type ) {
1666                 return new self( $this->getXPath()->query( $type, $this->node ) );
1667         }
1668
1669         /**
1670          * @return int
1671          */
1672         function getLength() {
1673                 if ( $this->node instanceof DOMNodeList ) {
1674                         return $this->node->length;
1675                 } else {
1676                         return false;
1677                 }
1678         }
1679
1680         /**
1681          * @param $i
1682          * @return bool|PPNode_DOM
1683          */
1684         function item( $i ) {
1685                 $item = $this->node->item( $i );
1686                 return $item ? new self( $item ) : false;
1687         }
1688
1689         /**
1690          * @return string
1691          */
1692         function getName() {
1693                 if ( $this->node instanceof DOMNodeList ) {
1694                         return '#nodelist';
1695                 } else {
1696                         return $this->node->nodeName;
1697                 }
1698         }
1699
1700         /**
1701          * Split a "<part>" node into an associative array containing:
1702          *  - name          PPNode name
1703          *  - index         String index
1704          *  - value         PPNode value
1705          *
1706          * @throws MWException
1707          * @return array
1708          */
1709         function splitArg() {
1710                 $xpath = $this->getXPath();
1711                 $names = $xpath->query( 'name', $this->node );
1712                 $values = $xpath->query( 'value', $this->node );
1713                 if ( !$names->length || !$values->length ) {
1714                         throw new MWException( 'Invalid brace node passed to ' . __METHOD__ );
1715                 }
1716                 $name = $names->item( 0 );
1717                 $index = $name->getAttribute( 'index' );
1718                 return array(
1719                         'name' => new self( $name ),
1720                         'index' => $index,
1721                         'value' => new self( $values->item( 0 ) ) );
1722         }
1723
1724         /**
1725          * Split an "<ext>" node into an associative array containing name, attr, inner and close
1726          * All values in the resulting array are PPNodes. Inner and close are optional.
1727          *
1728          * @throws MWException
1729          * @return array
1730          */
1731         function splitExt() {
1732                 $xpath = $this->getXPath();
1733                 $names = $xpath->query( 'name', $this->node );
1734                 $attrs = $xpath->query( 'attr', $this->node );
1735                 $inners = $xpath->query( 'inner', $this->node );
1736                 $closes = $xpath->query( 'close', $this->node );
1737                 if ( !$names->length || !$attrs->length ) {
1738                         throw new MWException( 'Invalid ext node passed to ' . __METHOD__ );
1739                 }
1740                 $parts = array(
1741                         'name' => new self( $names->item( 0 ) ),
1742                         'attr' => new self( $attrs->item( 0 ) ) );
1743                 if ( $inners->length ) {
1744                         $parts['inner'] = new self( $inners->item( 0 ) );
1745                 }
1746                 if ( $closes->length ) {
1747                         $parts['close'] = new self( $closes->item( 0 ) );
1748                 }
1749                 return $parts;
1750         }
1751
1752         /**
1753          * Split a "<h>" node
1754          * @throws MWException
1755          * @return array
1756          */
1757         function splitHeading() {
1758                 if ( $this->getName() !== 'h' ) {
1759                         throw new MWException( 'Invalid h node passed to ' . __METHOD__ );
1760                 }
1761                 return array(
1762                         'i' => $this->node->getAttribute( 'i' ),
1763                         'level' => $this->node->getAttribute( 'level' ),
1764                         'contents' => $this->getChildren()
1765                 );
1766         }
1767 }