includes/parser/Preprocessor_DOM.php

   1 <?php
   2 /**
   3  * Preprocessor using PHP's dom extension
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Parser
  22  */
  23
  24 /**
  25  * @ingroup Parser
  26  */
  27 class Preprocessor_DOM implements Preprocessor {
  28
  29         /**
  30          * @var Parser
  31          */
  32         var $parser;
  33
  34         var $memoryLimit;
  35
  36         const CACHE_VERSION = 1;
  37
  38         function __construct( $parser ) {
  39                 $this->parser = $parser;
  40                 $mem = ini_get( 'memory_limit' );
  41                 $this->memoryLimit = false;
  42                 if ( strval( $mem ) !== '' && $mem != -1 ) {
  43                         if ( preg_match( '/^\d+$/', $mem ) ) {
  44                                 $this->memoryLimit = $mem;
  45                         } elseif ( preg_match( '/^(\d+)M$/i', $mem, $m ) ) {
  46                                 $this->memoryLimit = $m[1] * 1048576;
  47                         }
  48                 }
  49         }
  50
  51         /**
  52          * @return PPFrame_DOM
  53          */
  54         function newFrame() {
  55                 return new PPFrame_DOM( $this );
  56         }
  57
  58         /**
  59          * @param $args array
  60          * @return PPCustomFrame_DOM
  61          */
  62         function newCustomFrame( $args ) {
  63                 return new PPCustomFrame_DOM( $this, $args );
  64         }
  65
  66         /**
  67          * @param $values
  68          * @return PPNode_DOM
  69          */
  70         function newPartNodeArray( $values ) {
  71                 //NOTE: DOM manipulation is slower than building & parsing XML! (or so Tim sais)
  72                 $xml = "<list>";
  73
  74                 foreach ( $values as $k => $val ) {
  75
  76                         if ( is_int( $k ) ) {
  77                                 $xml .= "<part><name index=\"$k\"/><value>" . htmlspecialchars( $val ) ."</value></part>";
  78                         } else {
  79                                 $xml .= "<part><name>" . htmlspecialchars( $k ) . "</name>=<value>" . htmlspecialchars( $val ) . "</value></part>";
  80                         }
  81                 }
  82
  83                 $xml .= "</list>";
  84
  85                 $dom = new DOMDocument();
  86                 $dom->loadXML( $xml );
  87                 $root = $dom->documentElement;
  88
  89                 $node = new PPNode_DOM( $root->childNodes );
  90                 return $node;
  91         }
  92
  93         /**
  94          * @throws MWException
  95          * @return bool
  96          */
  97         function memCheck() {
  98                 if ( $this->memoryLimit === false ) {
  99                         return true;
 100                 }
 101                 $usage = memory_get_usage();
 102                 if ( $usage > $this->memoryLimit * 0.9 ) {
 103                         $limit = intval( $this->memoryLimit * 0.9 / 1048576 + 0.5 );
 104                         throw new MWException( "Preprocessor hit 90% memory limit ($limit MB)" );
 105                 }
 106                 return $usage <= $this->memoryLimit * 0.8;
 107         }
 108
 109         /**
 110          * Preprocess some wikitext and return the document tree.
 111          * This is the ghost of Parser::replace_variables().
 112          *
 113          * @param $text String: the text to parse
 114          * @param $flags Integer: bitwise combination of:
 115          *          Parser::PTD_FOR_INCLUSION    Handle "<noinclude>" and "<includeonly>" as if the text is being
 116          *                                     included. Default is to assume a direct page view.
 117          *
 118          * The generated DOM tree must depend only on the input text and the flags.
 119          * The DOM tree must be the same in OT_HTML and OT_WIKI mode, to avoid a regression of bug 4899.
 120          *
 121          * Any flag added to the $flags parameter here, or any other parameter liable to cause a
 122          * change in the DOM tree for a given text, must be passed through the section identifier
 123          * in the section edit link and thus back to extractSections().
 124          *
 125          * The output of this function is currently only cached in process memory, but a persistent
 126          * cache may be implemented at a later date which takes further advantage of these strict
 127          * dependency requirements.
 128          *
 129          * @return PPNode_DOM
 130          */
 131         function preprocessToObj( $text, $flags = 0 ) {
 132                 wfProfileIn( __METHOD__ );
 133                 global $wgMemc, $wgPreprocessorCacheThreshold;
 134
 135                 $xml = false;
 136                 $cacheable = ( $wgPreprocessorCacheThreshold !== false
 137                         && strlen( $text ) > $wgPreprocessorCacheThreshold );
 138                 if ( $cacheable ) {
 139                         wfProfileIn( __METHOD__.'-cacheable' );
 140
 141                         $cacheKey = wfMemcKey( 'preprocess-xml', md5($text), $flags );
 142                         $cacheValue = $wgMemc->get( $cacheKey );
 143                         if ( $cacheValue ) {
 144                                 $version = substr( $cacheValue, 0, 8 );
 145                                 if ( intval( $version ) == self::CACHE_VERSION ) {
 146                                         $xml = substr( $cacheValue, 8 );
 147                                         // From the cache
 148                                         wfDebugLog( "Preprocessor", "Loaded preprocessor XML from memcached (key $cacheKey)" );
 149                                 }
 150                         }
 151                 }
 152                 if ( $xml === false ) {
 153                         if ( $cacheable ) {
 154                                 wfProfileIn( __METHOD__.'-cache-miss' );
 155                                 $xml = $this->preprocessToXml( $text, $flags );
 156                                 $cacheValue = sprintf( "%08d", self::CACHE_VERSION ) . $xml;
 157                                 $wgMemc->set( $cacheKey, $cacheValue, 86400 );
 158                                 wfProfileOut( __METHOD__.'-cache-miss' );
 159                                 wfDebugLog( "Preprocessor", "Saved preprocessor XML to memcached (key $cacheKey)" );
 160                         } else {
 161                                 $xml = $this->preprocessToXml( $text, $flags );
 162                         }
 163
 164                 }
 165
 166                 // Fail if the number of elements exceeds acceptable limits
 167                 // Do not attempt to generate the DOM
 168                 $this->parser->mGeneratedPPNodeCount += substr_count( $xml, '<' );
 169                 $max = $this->parser->mOptions->getMaxGeneratedPPNodeCount();
 170                 if ( $this->parser->mGeneratedPPNodeCount > $max ) {
 171                         throw new MWException( __METHOD__.': generated node count limit exceeded' );
 172                 }
 173
 174                 wfProfileIn( __METHOD__.'-loadXML' );
 175                 $dom = new DOMDocument;
 176                 wfSuppressWarnings();
 177                 $result = $dom->loadXML( $xml );
 178                 wfRestoreWarnings();
 179                 if ( !$result ) {
 180                         // Try running the XML through UtfNormal to get rid of invalid characters
 181                         $xml = UtfNormal::cleanUp( $xml );
 182                         // 1 << 19 == XML_PARSE_HUGE, needed so newer versions of libxml2 don't barf when the XML is >256 levels deep
 183                         $result = $dom->loadXML( $xml, 1 << 19 );
 184                         if ( !$result ) {
 185                                 throw new MWException( __METHOD__.' generated invalid XML' );
 186                         }
 187                 }
 188                 $obj = new PPNode_DOM( $dom->documentElement );
 189                 wfProfileOut( __METHOD__.'-loadXML' );
 190                 if ( $cacheable ) {
 191                         wfProfileOut( __METHOD__.'-cacheable' );
 192                 }
 193                 wfProfileOut( __METHOD__ );
 194                 return $obj;
 195         }
 196
 197         /**
 198          * @param $text string
 199          * @param $flags int
 200          * @return string
 201          */
 202         function preprocessToXml( $text, $flags = 0 ) {
 203                 wfProfileIn( __METHOD__ );
 204                 $rules = array(
 205                         '{' => array(
 206                                 'end' => '}',
 207                                 'names' => array(
 208                                         2 => 'template',
 209                                         3 => 'tplarg',
 210                                 ),
 211                                 'min' => 2,
 212                                 'max' => 3,
 213                         ),
 214                         '[' => array(
 215                                 'end' => ']',
 216                                 'names' => array( 2 => null ),
 217                                 'min' => 2,
 218                                 'max' => 2,
 219                         )
 220                 );
 221
 222                 $forInclusion = $flags & Parser::PTD_FOR_INCLUSION;
 223
 224                 $xmlishElements = $this->parser->getStripList();
 225                 $enableOnlyinclude = false;
 226                 if ( $forInclusion ) {
 227                         $ignoredTags = array( 'includeonly', '/includeonly' );
 228                         $ignoredElements = array( 'noinclude' );
 229                         $xmlishElements[] = 'noinclude';
 230                         if ( strpos( $text, '<onlyinclude>' ) !== false && strpos( $text, '</onlyinclude>' ) !== false ) {
 231                                 $enableOnlyinclude = true;
 232                         }
 233                 } else {
 234                         $ignoredTags = array( 'noinclude', '/noinclude', 'onlyinclude', '/onlyinclude' );
 235                         $ignoredElements = array( 'includeonly' );
 236                         $xmlishElements[] = 'includeonly';
 237                 }
 238                 $xmlishRegex = implode( '|', array_merge( $xmlishElements, $ignoredTags ) );
 239
 240                 // Use "A" modifier (anchored) instead of "^", because ^ doesn't work with an offset
 241                 $elementsRegex = "~($xmlishRegex)(?:\s|\/>|>)|(!--)~iA";
 242
 243                 $stack = new PPDStack;
 244
 245                 $searchBase = "[{<\n"; #}
 246                 $revText = strrev( $text ); // For fast reverse searches
 247                 $lengthText = strlen( $text );
 248
 249                 $i = 0;                     # Input pointer, starts out pointing to a pseudo-newline before the start
 250                 $accum =& $stack->getAccum();   # Current accumulator
 251                 $accum = '<root>';
 252                 $findEquals = false;            # True to find equals signs in arguments
 253                 $findPipe = false;              # True to take notice of pipe characters
 254                 $headingIndex = 1;
 255                 $inHeading = false;        # True if $i is inside a possible heading
 256                 $noMoreGT = false;         # True if there are no more greater-than (>) signs right of $i
 257                 $findOnlyinclude = $enableOnlyinclude; # True to ignore all input up to the next <onlyinclude>
 258                 $fakeLineStart = true;     # Do a line-start run without outputting an LF character
 259
 260                 while ( true ) {
 261                         //$this->memCheck();
 262
 263                         if ( $findOnlyinclude ) {
 264                                 // Ignore all input up to the next <onlyinclude>
 265                                 $startPos = strpos( $text, '<onlyinclude>', $i );
 266                                 if ( $startPos === false ) {
 267                                         // Ignored section runs to the end
 268                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i ) ) . '</ignore>';
 269                                         break;
 270                                 }
 271                                 $tagEndPos = $startPos + strlen( '<onlyinclude>' ); // past-the-end
 272                                 $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i, $tagEndPos - $i ) ) . '</ignore>';
 273                                 $i = $tagEndPos;
 274                                 $findOnlyinclude = false;
 275                         }
 276
 277                         if ( $fakeLineStart ) {
 278                                 $found = 'line-start';
 279                                 $curChar = '';
 280                         } else {
 281                                 # Find next opening brace, closing brace or pipe
 282                                 $search = $searchBase;
 283                                 if ( $stack->top === false ) {
 284                                         $currentClosing = '';
 285                                 } else {
 286                                         $currentClosing = $stack->top->close;
 287                                         $search .= $currentClosing;
 288                                 }
 289                                 if ( $findPipe ) {
 290                                         $search .= '|';
 291                                 }
 292                                 if ( $findEquals ) {
 293                                         // First equals will be for the template
 294                                         $search .= '=';
 295                                 }
 296                                 $rule = null;
 297                                 # Output literal section, advance input counter
 298                                 $literalLength = strcspn( $text, $search, $i );
 299                                 if ( $literalLength > 0 ) {
 300                                         $accum .= htmlspecialchars( substr( $text, $i, $literalLength ) );
 301                                         $i += $literalLength;
 302                                 }
 303                                 if ( $i >= $lengthText ) {
 304                                         if ( $currentClosing == "\n" ) {
 305                                                 // Do a past-the-end run to finish off the heading
 306                                                 $curChar = '';
 307                                                 $found = 'line-end';
 308                                         } else {
 309                                                 # All done
 310                                                 break;
 311                                         }
 312                                 } else {
 313                                         $curChar = $text[$i];
 314                                         if ( $curChar == '|' ) {
 315                                                 $found = 'pipe';
 316                                         } elseif ( $curChar == '=' ) {
 317                                                 $found = 'equals';
 318                                         } elseif ( $curChar == '<' ) {
 319                                                 $found = 'angle';
 320                                         } elseif ( $curChar == "\n" ) {
 321                                                 if ( $inHeading ) {
 322                                                         $found = 'line-end';
 323                                                 } else {
 324                                                         $found = 'line-start';
 325                                                 }
 326                                         } elseif ( $curChar == $currentClosing ) {
 327                                                 $found = 'close';
 328                                         } elseif ( isset( $rules[$curChar] ) ) {
 329                                                 $found = 'open';
 330                                                 $rule = $rules[$curChar];
 331                                         } else {
 332                                                 # Some versions of PHP have a strcspn which stops on null characters
 333                                                 # Ignore and continue
 334                                                 ++$i;
 335                                                 continue;
 336                                         }
 337                                 }
 338                         }
 339
 340                         if ( $found == 'angle' ) {
 341                                 $matches = false;
 342                                 // Handle </onlyinclude>
 343                                 if ( $enableOnlyinclude && substr( $text, $i, strlen( '</onlyinclude>' ) ) == '</onlyinclude>' ) {
 344                                         $findOnlyinclude = true;
 345                                         continue;
 346                                 }
 347
 348                                 // Determine element name
 349                                 if ( !preg_match( $elementsRegex, $text, $matches, 0, $i + 1 ) ) {
 350                                         // Element name missing or not listed
 351                                         $accum .= '&lt;';
 352                                         ++$i;
 353                                         continue;
 354                                 }
 355                                 // Handle comments
 356                                 if ( isset( $matches[2] ) && $matches[2] == '!--' ) {
 357                                         // To avoid leaving blank lines, when a comment is both preceded
 358                                         // and followed by a newline (ignoring spaces), trim leading and
 359                                         // trailing spaces and one of the newlines.
 360
 361                                         // Find the end
 362                                         $endPos = strpos( $text, '-->', $i + 4 );
 363                                         if ( $endPos === false ) {
 364                                                 // Unclosed comment in input, runs to end
 365                                                 $inner = substr( $text, $i );
 366                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 367                                                 $i = $lengthText;
 368                                         } else {
 369                                                 // Search backwards for leading whitespace
 370                                                 $wsStart = $i ? ( $i - strspn( $revText, ' ', $lengthText - $i ) ) : 0;
 371                                                 // Search forwards for trailing whitespace
 372                                                 // $wsEnd will be the position of the last space (or the '>' if there's none)
 373                                                 $wsEnd = $endPos + 2 + strspn( $text, ' ', $endPos + 3 );
 374                                                 // Eat the line if possible
 375                                                 // TODO: This could theoretically be done if $wsStart == 0, i.e. for comments at
 376                                                 // the overall start. That's not how Sanitizer::removeHTMLcomments() did it, but
 377                                                 // it's a possible beneficial b/c break.
 378                                                 if ( $wsStart > 0 && substr( $text, $wsStart - 1, 1 ) == "\n"
 379                                                         && substr( $text, $wsEnd + 1, 1 ) == "\n" )
 380                                                 {
 381                                                         $startPos = $wsStart;
 382                                                         $endPos = $wsEnd + 1;
 383                                                         // Remove leading whitespace from the end of the accumulator
 384                                                         // Sanity check first though
 385                                                         $wsLength = $i - $wsStart;
 386                                                         if ( $wsLength > 0 && substr( $accum, -$wsLength ) === str_repeat( ' ', $wsLength ) ) {
 387                                                                 $accum = substr( $accum, 0, -$wsLength );
 388                                                         }
 389                                                         // Do a line-start run next time to look for headings after the comment
 390                                                         $fakeLineStart = true;
 391                                                 } else {
 392                                                         // No line to eat, just take the comment itself
 393                                                         $startPos = $i;
 394                                                         $endPos += 2;
 395                                                 }
 396
 397                                                 if ( $stack->top ) {
 398                                                         $part = $stack->top->getCurrentPart();
 399                                                         if ( ! (isset( $part->commentEnd ) && $part->commentEnd == $wsStart - 1 )) {
 400                                                                 $part->visualEnd = $wsStart;
 401                                                         }
 402                                                         // Else comments abutting, no change in visual end
 403                                                         $part->commentEnd = $endPos;
 404                                                 }
 405                                                 $i = $endPos + 1;
 406                                                 $inner = substr( $text, $startPos, $endPos - $startPos + 1 );
 407                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 408                                         }
 409                                         continue;
 410                                 }
 411                                 $name = $matches[1];
 412                                 $lowerName = strtolower( $name );
 413                                 $attrStart = $i + strlen( $name ) + 1;
 414
 415                                 // Find end of tag
 416                                 $tagEndPos = $noMoreGT ? false : strpos( $text, '>', $attrStart );
 417                                 if ( $tagEndPos === false ) {
 418                                         // Infinite backtrack
 419                                         // Disable tag search to prevent worst-case O(N^2) performance
 420                                         $noMoreGT = true;
 421                                         $accum .= '&lt;';
 422                                         ++$i;
 423                                         continue;
 424                                 }
 425
 426                                 // Handle ignored tags
 427                                 if ( in_array( $lowerName, $ignoredTags ) ) {
 428                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i, $tagEndPos - $i + 1 ) ) . '</ignore>';
 429                                         $i = $tagEndPos + 1;
 430                                         continue;
 431                                 }
 432
 433                                 $tagStartPos = $i;
 434                                 if ( $text[$tagEndPos-1] == '/' ) {
 435                                         $attrEnd = $tagEndPos - 1;
 436                                         $inner = null;
 437                                         $i = $tagEndPos + 1;
 438                                         $close = '';
 439                                 } else {
 440                                         $attrEnd = $tagEndPos;
 441                                         // Find closing tag
 442                                         if ( preg_match( "/<\/" . preg_quote( $name, '/' ) . "\s*>/i",
 443                                                         $text, $matches, PREG_OFFSET_CAPTURE, $tagEndPos + 1 ) )
 444                                         {
 445                                                 $inner = substr( $text, $tagEndPos + 1, $matches[0][1] - $tagEndPos - 1 );
 446                                                 $i = $matches[0][1] + strlen( $matches[0][0] );
 447                                                 $close = '<close>' . htmlspecialchars( $matches[0][0] ) . '</close>';
 448                                         } else {
 449                                                 // No end tag -- let it run out to the end of the text.
 450                                                 $inner = substr( $text, $tagEndPos + 1 );
 451                                                 $i = $lengthText;
 452                                                 $close = '';
 453                                         }
 454                                 }
 455                                 // <includeonly> and <noinclude> just become <ignore> tags
 456                                 if ( in_array( $lowerName, $ignoredElements ) ) {
 457                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $tagStartPos, $i - $tagStartPos ) )
 458                                                 . '</ignore>';
 459                                         continue;
 460                                 }
 461
 462                                 $accum .= '<ext>';
 463                                 if ( $attrEnd <= $attrStart ) {
 464                                         $attr = '';
 465                                 } else {
 466                                         $attr = substr( $text, $attrStart, $attrEnd - $attrStart );
 467                                 }
 468                                 $accum .= '<name>' . htmlspecialchars( $name ) . '</name>' .
 469                                         // Note that the attr element contains the whitespace between name and attribute,
 470                                         // this is necessary for precise reconstruction during pre-save transform.
 471                                         '<attr>' . htmlspecialchars( $attr ) . '</attr>';
 472                                 if ( $inner !== null ) {
 473                                         $accum .= '<inner>' . htmlspecialchars( $inner ) . '</inner>';
 474                                 }
 475                                 $accum .= $close . '</ext>';
 476                         } elseif ( $found == 'line-start' ) {
 477                                 // Is this the start of a heading?
 478                                 // Line break belongs before the heading element in any case
 479                                 if ( $fakeLineStart ) {
 480                                         $fakeLineStart = false;
 481                                 } else {
 482                                         $accum .= $curChar;
 483                                         $i++;
 484                                 }
 485
 486                                 $count = strspn( $text, '=', $i, 6 );
 487                                 if ( $count == 1 && $findEquals ) {
 488                                         // DWIM: This looks kind of like a name/value separator
 489                                         // Let's let the equals handler have it and break the potential heading
 490                                         // This is heuristic, but AFAICT the methods for completely correct disambiguation are very complex.
 491                                 } elseif ( $count > 0 ) {
 492                                         $piece = array(
 493                                                 'open' => "\n",
 494                                                 'close' => "\n",
 495                                                 'parts' => array( new PPDPart( str_repeat( '=', $count ) ) ),
 496                                                 'startPos' => $i,
 497                                                 'count' => $count );
 498                                         $stack->push( $piece );
 499                                         $accum =& $stack->getAccum();
 500                                         $flags = $stack->getFlags();
 501                                         extract( $flags );
 502                                         $i += $count;
 503                                 }
 504                         } elseif ( $found == 'line-end' ) {
 505                                 $piece = $stack->top;
 506                                 // A heading must be open, otherwise \n wouldn't have been in the search list
 507                                 assert( '$piece->open == "\n"' );
 508                                 $part = $piece->getCurrentPart();
 509                                 // Search back through the input to see if it has a proper close
 510                                 // Do this using the reversed string since the other solutions (end anchor, etc.) are inefficient
 511                                 $wsLength = strspn( $revText, " \t", $lengthText - $i );
 512                                 $searchStart = $i - $wsLength;
 513                                 if ( isset( $part->commentEnd ) && $searchStart - 1 == $part->commentEnd ) {
 514                                         // Comment found at line end
 515                                         // Search for equals signs before the comment
 516                                         $searchStart = $part->visualEnd;
 517                                         $searchStart -= strspn( $revText, " \t", $lengthText - $searchStart );
 518                                 }
 519                                 $count = $piece->count;
 520                                 $equalsLength = strspn( $revText, '=', $lengthText - $searchStart );
 521                                 if ( $equalsLength > 0 ) {
 522                                         if ( $searchStart - $equalsLength == $piece->startPos ) {
 523                                                 // This is just a single string of equals signs on its own line
 524                                                 // Replicate the doHeadings behaviour /={count}(.+)={count}/
 525                                                 // First find out how many equals signs there really are (don't stop at 6)
 526                                                 $count = $equalsLength;
 527                                                 if ( $count < 3 ) {
 528                                                         $count = 0;
 529                                                 } else {
 530                                                         $count = min( 6, intval( ( $count - 1 ) / 2 ) );
 531                                                 }
 532                                         } else {
 533                                                 $count = min( $equalsLength, $count );
 534                                         }
 535                                         if ( $count > 0 ) {
 536                                                 // Normal match, output <h>
 537                                                 $element = "<h level=\"$count\" i=\"$headingIndex\">$accum</h>";
 538                                                 $headingIndex++;
 539                                         } else {
 540                                                 // Single equals sign on its own line, count=0
 541                                                 $element = $accum;
 542                                         }
 543                                 } else {
 544                                         // No match, no <h>, just pass down the inner text
 545                                         $element = $accum;
 546                                 }
 547                                 // Unwind the stack
 548                                 $stack->pop();
 549                                 $accum =& $stack->getAccum();
 550                                 $flags = $stack->getFlags();
 551                                 extract( $flags );
 552
 553                                 // Append the result to the enclosing accumulator
 554                                 $accum .= $element;
 555                                 // Note that we do NOT increment the input pointer.
 556                                 // This is because the closing linebreak could be the opening linebreak of
 557                                 // another heading. Infinite loops are avoided because the next iteration MUST
 558                                 // hit the heading open case above, which unconditionally increments the
 559                                 // input pointer.
 560                         } elseif ( $found == 'open' ) {
 561                                 # count opening brace characters
 562                                 $count = strspn( $text, $curChar, $i );
 563
 564                                 # we need to add to stack only if opening brace count is enough for one of the rules
 565                                 if ( $count >= $rule['min'] ) {
 566                                         # Add it to the stack
 567                                         $piece = array(
 568                                                 'open' => $curChar,
 569                                                 'close' => $rule['end'],
 570                                                 'count' => $count,
 571                                                 'lineStart' => ($i > 0 && $text[$i-1] == "\n"),
 572                                         );
 573
 574                                         $stack->push( $piece );
 575                                         $accum =& $stack->getAccum();
 576                                         $flags = $stack->getFlags();
 577                                         extract( $flags );
 578                                 } else {
 579                                         # Add literal brace(s)
 580                                         $accum .= htmlspecialchars( str_repeat( $curChar, $count ) );
 581                                 }
 582                                 $i += $count;
 583                         } elseif ( $found == 'close' ) {
 584                                 $piece = $stack->top;
 585                                 # lets check if there are enough characters for closing brace
 586                                 $maxCount = $piece->count;
 587                                 $count = strspn( $text, $curChar, $i, $maxCount );
 588
 589                                 # check for maximum matching characters (if there are 5 closing
 590                                 # characters, we will probably need only 3 - depending on the rules)
 591                                 $rule = $rules[$piece->open];
 592                                 if ( $count > $rule['max'] ) {
 593                                         # The specified maximum exists in the callback array, unless the caller
 594                                         # has made an error
 595                                         $matchingCount = $rule['max'];
 596                                 } else {
 597                                         # Count is less than the maximum
 598                                         # Skip any gaps in the callback array to find the true largest match
 599                                         # Need to use array_key_exists not isset because the callback can be null
 600                                         $matchingCount = $count;
 601                                         while ( $matchingCount > 0 && !array_key_exists( $matchingCount, $rule['names'] ) ) {
 602                                                 --$matchingCount;
 603                                         }
 604                                 }
 605
 606                                 if ( $matchingCount <= 0 ) {
 607                                         # No matching element found in callback array
 608                                         # Output a literal closing brace and continue
 609                                         $accum .= htmlspecialchars( str_repeat( $curChar, $count ) );
 610                                         $i += $count;
 611                                         continue;
 612                                 }
 613                                 $name = $rule['names'][$matchingCount];
 614                                 if ( $name === null ) {
 615                                         // No element, just literal text
 616                                         $element = $piece->breakSyntax( $matchingCount ) . str_repeat( $rule['end'], $matchingCount );
 617                                 } else {
 618                                         # Create XML element
 619                                         # Note: $parts is already XML, does not need to be encoded further
 620                                         $parts = $piece->parts;
 621                                         $title = $parts[0]->out;
 622                                         unset( $parts[0] );
 623
 624                                         # The invocation is at the start of the line if lineStart is set in
 625                                         # the stack, and all opening brackets are used up.
 626                                         if ( $maxCount == $matchingCount && !empty( $piece->lineStart ) ) {
 627                                                 $attr = ' lineStart="1"';
 628                                         } else {
 629                                                 $attr = '';
 630                                         }
 631
 632                                         $element = "<$name$attr>";
 633                                         $element .= "<title>$title</title>";
 634                                         $argIndex = 1;
 635                                         foreach ( $parts as $part ) {
 636                                                 if ( isset( $part->eqpos ) ) {
 637                                                         $argName = substr( $part->out, 0, $part->eqpos );
 638                                                         $argValue = substr( $part->out, $part->eqpos + 1 );
 639                                                         $element .= "<part><name>$argName</name>=<value>$argValue</value></part>";
 640                                                 } else {
 641                                                         $element .= "<part><name index=\"$argIndex\" /><value>{$part->out}</value></part>";
 642                                                         $argIndex++;
 643                                                 }
 644                                         }
 645                                         $element .= "</$name>";
 646                                 }
 647
 648                                 # Advance input pointer
 649                                 $i += $matchingCount;
 650
 651                                 # Unwind the stack
 652                                 $stack->pop();
 653                                 $accum =& $stack->getAccum();
 654
 655                                 # Re-add the old stack element if it still has unmatched opening characters remaining
 656                                 if ( $matchingCount < $piece->count ) {
 657                                         $piece->parts = array( new PPDPart );
 658                                         $piece->count -= $matchingCount;
 659                                         # do we still qualify for any callback with remaining count?
 660                                         $names = $rules[$piece->open]['names'];
 661                                         $skippedBraces = 0;
 662                                         $enclosingAccum =& $accum;
 663                                         while ( $piece->count ) {
 664                                                 if ( array_key_exists( $piece->count, $names ) ) {
 665                                                         $stack->push( $piece );
 666                                                         $accum =& $stack->getAccum();
 667                                                         break;
 668                                                 }
 669                                                 --$piece->count;
 670                                                 $skippedBraces ++;
 671                                         }
 672                                         $enclosingAccum .= str_repeat( $piece->open, $skippedBraces );
 673                                 }
 674                                 $flags = $stack->getFlags();
 675                                 extract( $flags );
 676
 677                                 # Add XML element to the enclosing accumulator
 678                                 $accum .= $element;
 679                         } elseif ( $found == 'pipe' ) {
 680                                 $findEquals = true; // shortcut for getFlags()
 681                                 $stack->addPart();
 682                                 $accum =& $stack->getAccum();
 683                                 ++$i;
 684                         } elseif ( $found == 'equals' ) {
 685                                 $findEquals = false; // shortcut for getFlags()
 686                                 $stack->getCurrentPart()->eqpos = strlen( $accum );
 687                                 $accum .= '=';
 688                                 ++$i;
 689                         }
 690                 }
 691
 692                 # Output any remaining unclosed brackets
 693                 foreach ( $stack->stack as $piece ) {
 694                         $stack->rootAccum .= $piece->breakSyntax();
 695                 }
 696                 $stack->rootAccum .= '</root>';
 697                 $xml = $stack->rootAccum;
 698
 699                 wfProfileOut( __METHOD__ );
 700
 701                 return $xml;
 702         }
 703 }
 704
 705 /**
 706  * Stack class to help Preprocessor::preprocessToObj()
 707  * @ingroup Parser
 708  */
 709 class PPDStack {
 710         var $stack, $rootAccum;
 711
 712         /**
 713          * @var PPDStack
 714          */
 715         var $top;
 716         var $out;
 717         var $elementClass = 'PPDStackElement';
 718
 719         static $false = false;
 720
 721         function __construct() {
 722                 $this->stack = array();
 723                 $this->top = false;
 724                 $this->rootAccum = '';
 725                 $this->accum =& $this->rootAccum;
 726         }
 727
 728         /**
 729          * @return int
 730          */
 731         function count() {
 732                 return count( $this->stack );
 733         }
 734
 735         function &getAccum() {
 736                 return $this->accum;
 737         }
 738
 739         function getCurrentPart() {
 740                 if ( $this->top === false ) {
 741                         return false;
 742                 } else {
 743                         return $this->top->getCurrentPart();
 744                 }
 745         }
 746
 747         function push( $data ) {
 748                 if ( $data instanceof $this->elementClass ) {
 749                         $this->stack[] = $data;
 750                 } else {
 751                         $class = $this->elementClass;
 752                         $this->stack[] = new $class( $data );
 753                 }
 754                 $this->top = $this->stack[ count( $this->stack ) - 1 ];
 755                 $this->accum =& $this->top->getAccum();
 756         }
 757
 758         function pop() {
 759                 if ( !count( $this->stack ) ) {
 760                         throw new MWException( __METHOD__.': no elements remaining' );
 761                 }
 762                 $temp = array_pop( $this->stack );
 763
 764                 if ( count( $this->stack ) ) {
 765                         $this->top = $this->stack[ count( $this->stack ) - 1 ];
 766                         $this->accum =& $this->top->getAccum();
 767                 } else {
 768                         $this->top = self::$false;
 769                         $this->accum =& $this->rootAccum;
 770                 }
 771                 return $temp;
 772         }
 773
 774         function addPart( $s = '' ) {
 775                 $this->top->addPart( $s );
 776                 $this->accum =& $this->top->getAccum();
 777         }
 778
 779         /**
 780          * @return array
 781          */
 782         function getFlags() {
 783                 if ( !count( $this->stack ) ) {
 784                         return array(
 785                                 'findEquals' => false,
 786                                 'findPipe' => false,
 787                                 'inHeading' => false,
 788                         );
 789                 } else {
 790                         return $this->top->getFlags();
 791                 }
 792         }
 793 }
 794
 795 /**
 796  * @ingroup Parser
 797  */
 798 class PPDStackElement {
 799         var $open,                      // Opening character (\n for heading)
 800                 $close,             // Matching closing character
 801                 $count,             // Number of opening characters found (number of "=" for heading)
 802                 $parts,             // Array of PPDPart objects describing pipe-separated parts.
 803                 $lineStart;         // True if the open char appeared at the start of the input line. Not set for headings.
 804
 805         var $partClass = 'PPDPart';
 806
 807         function __construct( $data = array() ) {
 808                 $class = $this->partClass;
 809                 $this->parts = array( new $class );
 810
 811                 foreach ( $data as $name => $value ) {
 812                         $this->$name = $value;
 813                 }
 814         }
 815
 816         function &getAccum() {
 817                 return $this->parts[count($this->parts) - 1]->out;
 818         }
 819
 820         function addPart( $s = '' ) {
 821                 $class = $this->partClass;
 822                 $this->parts[] = new $class( $s );
 823         }
 824
 825         function getCurrentPart() {
 826                 return $this->parts[count($this->parts) - 1];
 827         }
 828
 829         /**
 830          * @return array
 831          */
 832         function getFlags() {
 833                 $partCount = count( $this->parts );
 834                 $findPipe = $this->open != "\n" && $this->open != '[';
 835                 return array(
 836                         'findPipe' => $findPipe,
 837                         'findEquals' => $findPipe && $partCount > 1 && !isset( $this->parts[$partCount - 1]->eqpos ),
 838                         'inHeading' => $this->open == "\n",
 839                 );
 840         }
 841
 842         /**
 843          * Get the output string that would result if the close is not found.
 844          *
 845          * @return string
 846          */
 847         function breakSyntax( $openingCount = false ) {
 848                 if ( $this->open == "\n" ) {
 849                         $s = $this->parts[0]->out;
 850                 } else {
 851                         if ( $openingCount === false ) {
 852                                 $openingCount = $this->count;
 853                         }
 854                         $s = str_repeat( $this->open, $openingCount );
 855                         $first = true;
 856                         foreach ( $this->parts as $part ) {
 857                                 if ( $first ) {
 858                                         $first = false;
 859                                 } else {
 860                                         $s .= '|';
 861                                 }
 862                                 $s .= $part->out;
 863                         }
 864                 }
 865                 return $s;
 866         }
 867 }
 868
 869 /**
 870  * @ingroup Parser
 871  */
 872 class PPDPart {
 873         var $out; // Output accumulator string
 874
 875         // Optional member variables:
 876         //   eqpos        Position of equals sign in output accumulator
 877         //   commentEnd   Past-the-end input pointer for the last comment encountered
 878         //   visualEnd    Past-the-end input pointer for the end of the accumulator minus comments
 879
 880         function __construct( $out = '' ) {
 881                 $this->out = $out;
 882         }
 883 }
 884
 885 /**
 886  * An expansion frame, used as a context to expand the result of preprocessToObj()
 887  * @ingroup Parser
 888  */
 889 class PPFrame_DOM implements PPFrame {
 890
 891         /**
 892          * @var Preprocessor
 893          */
 894         var $preprocessor;
 895
 896         /**
 897          * @var Parser
 898          */
 899         var $parser;
 900
 901         /**
 902          * @var Title
 903          */
 904         var $title;
 905         var $titleCache;
 906
 907         /**
 908          * Hashtable listing templates which are disallowed for expansion in this frame,
 909          * having been encountered previously in parent frames.
 910          */
 911         var $loopCheckHash;
 912
 913         /**
 914          * Recursion depth of this frame, top = 0
 915          * Note that this is NOT the same as expansion depth in expand()
 916          */
 917         var $depth;
 918
 919
 920         /**
 921          * Construct a new preprocessor frame.
 922          * @param $preprocessor Preprocessor The parent preprocessor
 923          */
 924         function __construct( $preprocessor ) {
 925                 $this->preprocessor = $preprocessor;
 926                 $this->parser = $preprocessor->parser;
 927                 $this->title = $this->parser->mTitle;
 928                 $this->titleCache = array( $this->title ? $this->title->getPrefixedDBkey() : false );
 929                 $this->loopCheckHash = array();
 930                 $this->depth = 0;
 931         }
 932
 933         /**
 934          * Create a new child frame
 935          * $args is optionally a multi-root PPNode or array containing the template arguments
 936          *
 937          * @return PPTemplateFrame_DOM
 938          */
 939         function newChild( $args = false, $title = false, $indexOffset = 0 ) {
 940                 $namedArgs = array();
 941                 $numberedArgs = array();
 942                 if ( $title === false ) {
 943                         $title = $this->title;
 944                 }
 945                 if ( $args !== false ) {
 946                         $xpath = false;
 947                         if ( $args instanceof PPNode ) {
 948                                 $args = $args->node;
 949                         }
 950                         foreach ( $args as $arg ) {
 951                                 if ( $arg instanceof PPNode ) {
 952                                         $arg = $arg->node;
 953                                 }
 954                                 if ( !$xpath ) {
 955                                         $xpath = new DOMXPath( $arg->ownerDocument );
 956                                 }
 957
 958                                 $nameNodes = $xpath->query( 'name', $arg );
 959                                 $value = $xpath->query( 'value', $arg );
 960                                 if ( $nameNodes->item( 0 )->hasAttributes() ) {
 961                                         // Numbered parameter
 962                                         $index = $nameNodes->item( 0 )->attributes->getNamedItem( 'index' )->textContent;
 963                                         $index = $index - $indexOffset;
 964                                         $numberedArgs[$index] = $value->item( 0 );
 965                                         unset( $namedArgs[$index] );
 966                                 } else {
 967                                         // Named parameter
 968                                         $name = trim( $this->expand( $nameNodes->item( 0 ), PPFrame::STRIP_COMMENTS ) );
 969                                         $namedArgs[$name] = $value->item( 0 );
 970                                         unset( $numberedArgs[$name] );
 971                                 }
 972                         }
 973                 }
 974                 return new PPTemplateFrame_DOM( $this->preprocessor, $this, $numberedArgs, $namedArgs, $title );
 975         }
 976
 977         /**
 978          * @throws MWException
 979          * @param $root
 980          * @param $flags int
 981          * @return string
 982          */
 983         function expand( $root, $flags = 0 ) {
 984                 static $expansionDepth = 0;
 985                 if ( is_string( $root ) ) {
 986                         return $root;
 987                 }
 988
 989                 if ( ++$this->parser->mPPNodeCount > $this->parser->mOptions->getMaxPPNodeCount() ) {
 990                         $this->parser->limitationWarn( 'node-count-exceeded',
 991                                 $this->parser->mPPNodeCount,
 992                                 $this->parser->mOptions->getMaxPPNodeCount()
 993                         );
 994                         return '<span class="error">Node-count limit exceeded</span>';
 995                 }
 996
 997                 if ( $expansionDepth > $this->parser->mOptions->getMaxPPExpandDepth() ) {
 998                         $this->parser->limitationWarn( 'expansion-depth-exceeded',
 999                                 $expansionDepth,
1000                                 $this->parser->mOptions->getMaxPPExpandDepth()
1001                         );
1002                         return '<span class="error">Expansion depth limit exceeded</span>';
1003                 }
1004                 wfProfileIn( __METHOD__ );
1005                 ++$expansionDepth;
1006                 if ( $expansionDepth > $this->parser->mHighestExpansionDepth ) {
1007                         $this->parser->mHighestExpansionDepth = $expansionDepth;
1008                 }
1009
1010                 if ( $root instanceof PPNode_DOM ) {
1011                         $root = $root->node;
1012                 }
1013                 if ( $root instanceof DOMDocument ) {
1014                         $root = $root->documentElement;
1015                 }
1016
1017                 $outStack = array( '', '' );
1018                 $iteratorStack = array( false, $root );
1019                 $indexStack = array( 0, 0 );
1020
1021                 while ( count( $iteratorStack ) > 1 ) {
1022                         $level = count( $outStack ) - 1;
1023                         $iteratorNode =& $iteratorStack[ $level ];
1024                         $out =& $outStack[$level];
1025                         $index =& $indexStack[$level];
1026
1027                         if ( $iteratorNode instanceof PPNode_DOM ) $iteratorNode = $iteratorNode->node;
1028
1029                         if ( is_array( $iteratorNode ) ) {
1030                                 if ( $index >= count( $iteratorNode ) ) {
1031                                         // All done with this iterator
1032                                         $iteratorStack[$level] = false;
1033                                         $contextNode = false;
1034                                 } else {
1035                                         $contextNode = $iteratorNode[$index];
1036                                         $index++;
1037                                 }
1038                         } elseif ( $iteratorNode instanceof DOMNodeList ) {
1039                                 if ( $index >= $iteratorNode->length ) {
1040                                         // All done with this iterator
1041                                         $iteratorStack[$level] = false;
1042                                         $contextNode = false;
1043                                 } else {
1044                                         $contextNode = $iteratorNode->item( $index );
1045                                         $index++;
1046                                 }
1047                         } else {
1048                                 // Copy to $contextNode and then delete from iterator stack,
1049                                 // because this is not an iterator but we do have to execute it once
1050                                 $contextNode = $iteratorStack[$level];
1051                                 $iteratorStack[$level] = false;
1052                         }
1053
1054                         if ( $contextNode instanceof PPNode_DOM ) {
1055                                 $contextNode = $contextNode->node;
1056                         }
1057
1058                         $newIterator = false;
1059
1060                         if ( $contextNode === false ) {
1061                                 // nothing to do
1062                         } elseif ( is_string( $contextNode ) ) {
1063                                 $out .= $contextNode;
1064                         } elseif ( is_array( $contextNode ) || $contextNode instanceof DOMNodeList ) {
1065                                 $newIterator = $contextNode;
1066                         } elseif ( $contextNode instanceof DOMNode ) {
1067                                 if ( $contextNode->nodeType == XML_TEXT_NODE ) {
1068                                         $out .= $contextNode->nodeValue;
1069                                 } elseif ( $contextNode->nodeName == 'template' ) {
1070                                         # Double-brace expansion
1071                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1072                                         $titles = $xpath->query( 'title', $contextNode );
1073                                         $title = $titles->item( 0 );
1074                                         $parts = $xpath->query( 'part', $contextNode );
1075                                         if ( $flags & PPFrame::NO_TEMPLATES ) {
1076                                                 $newIterator = $this->virtualBracketedImplode( '{{', '|', '}}', $title, $parts );
1077                                         } else {
1078                                                 $lineStart = $contextNode->getAttribute( 'lineStart' );
1079                                                 $params = array(
1080                                                         'title' => new PPNode_DOM( $title ),
1081                                                         'parts' => new PPNode_DOM( $parts ),
1082                                                         'lineStart' => $lineStart );
1083                                                 $ret = $this->parser->braceSubstitution( $params, $this );
1084                                                 if ( isset( $ret['object'] ) ) {
1085                                                         $newIterator = $ret['object'];
1086                                                 } else {
1087                                                         $out .= $ret['text'];
1088                                                 }
1089                                         }
1090                                 } elseif ( $contextNode->nodeName == 'tplarg' ) {
1091                                         # Triple-brace expansion
1092                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1093                                         $titles = $xpath->query( 'title', $contextNode );
1094                                         $title = $titles->item( 0 );
1095                                         $parts = $xpath->query( 'part', $contextNode );
1096                                         if ( $flags & PPFrame::NO_ARGS ) {
1097                                                 $newIterator = $this->virtualBracketedImplode( '{{{', '|', '}}}', $title, $parts );
1098                                         } else {
1099                                                 $params = array(
1100                                                         'title' => new PPNode_DOM( $title ),
1101                                                         'parts' => new PPNode_DOM( $parts ) );
1102                                                 $ret = $this->parser->argSubstitution( $params, $this );
1103                                                 if ( isset( $ret['object'] ) ) {
1104                                                         $newIterator = $ret['object'];
1105                                                 } else {
1106                                                         $out .= $ret['text'];
1107                                                 }
1108                                         }
1109                                 } elseif ( $contextNode->nodeName == 'comment' ) {
1110                                         # HTML-style comment
1111                                         # Remove it in HTML, pre+remove and STRIP_COMMENTS modes
1112                                         if ( $this->parser->ot['html']
1113                                                 || ( $this->parser->ot['pre'] && $this->parser->mOptions->getRemoveComments() )
1114                                                 || ( $flags & PPFrame::STRIP_COMMENTS ) )
1115                                         {
1116                                                 $out .= '';
1117                                         }
1118                                         # Add a strip marker in PST mode so that pstPass2() can run some old-fashioned regexes on the result
1119                                         # Not in RECOVER_COMMENTS mode (extractSections) though
1120                                         elseif ( $this->parser->ot['wiki'] && ! ( $flags & PPFrame::RECOVER_COMMENTS ) ) {
1121                                                 $out .= $this->parser->insertStripItem( $contextNode->textContent );
1122                                         }
1123                                         # Recover the literal comment in RECOVER_COMMENTS and pre+no-remove
1124                                         else {
1125                                                 $out .= $contextNode->textContent;
1126                                         }
1127                                 } elseif ( $contextNode->nodeName == 'ignore' ) {
1128                                         # Output suppression used by <includeonly> etc.
1129                                         # OT_WIKI will only respect <ignore> in substed templates.
1130                                         # The other output types respect it unless NO_IGNORE is set.
1131                                         # extractSections() sets NO_IGNORE and so never respects it.
1132                                         if ( ( !isset( $this->parent ) && $this->parser->ot['wiki'] ) || ( $flags & PPFrame::NO_IGNORE ) ) {
1133                                                 $out .= $contextNode->textContent;
1134                                         } else {
1135                                                 $out .= '';
1136                                         }
1137                                 } elseif ( $contextNode->nodeName == 'ext' ) {
1138                                         # Extension tag
1139                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1140                                         $names = $xpath->query( 'name', $contextNode );
1141                                         $attrs = $xpath->query( 'attr', $contextNode );
1142                                         $inners = $xpath->query( 'inner', $contextNode );
1143                                         $closes = $xpath->query( 'close', $contextNode );
1144                                         $params = array(
1145                                                 'name' => new PPNode_DOM( $names->item( 0 ) ),
1146                                                 'attr' => $attrs->length > 0 ? new PPNode_DOM( $attrs->item( 0 ) ) : null,
1147                                                 'inner' => $inners->length > 0 ? new PPNode_DOM( $inners->item( 0 ) ) : null,
1148                                                 'close' => $closes->length > 0 ? new PPNode_DOM( $closes->item( 0 ) ) : null,
1149                                         );
1150                                         $out .= $this->parser->extensionSubstitution( $params, $this );
1151                                 } elseif ( $contextNode->nodeName == 'h' ) {
1152                                         # Heading
1153                                         $s = $this->expand( $contextNode->childNodes, $flags );
1154
1155                                         # Insert a heading marker only for <h> children of <root>
1156                                         # This is to stop extractSections from going over multiple tree levels
1157                                         if ( $contextNode->parentNode->nodeName == 'root'
1158                                           && $this->parser->ot['html'] )
1159                                         {
1160                                                 # Insert heading index marker
1161                                                 $headingIndex = $contextNode->getAttribute( 'i' );
1162                                                 $titleText = $this->title->getPrefixedDBkey();
1163                                                 $this->parser->mHeadings[] = array( $titleText, $headingIndex );
1164                                                 $serial = count( $this->parser->mHeadings ) - 1;
1165                                                 $marker = "{$this->parser->mUniqPrefix}-h-$serial-" . Parser::MARKER_SUFFIX;
1166                                                 $count = $contextNode->getAttribute( 'level' );
1167                                                 $s = substr( $s, 0, $count ) . $marker . substr( $s, $count );
1168                                                 $this->parser->mStripState->addGeneral( $marker, '' );
1169                                         }
1170                                         $out .= $s;
1171                                 } else {
1172                                         # Generic recursive expansion
1173                                         $newIterator = $contextNode->childNodes;
1174                                 }
1175                         } else {
1176                                 wfProfileOut( __METHOD__ );
1177                                 throw new MWException( __METHOD__.': Invalid parameter type' );
1178                         }
1179
1180                         if ( $newIterator !== false ) {
1181                                 if ( $newIterator instanceof PPNode_DOM ) {
1182                                         $newIterator = $newIterator->node;
1183                                 }
1184                                 $outStack[] = '';
1185                                 $iteratorStack[] = $newIterator;
1186                                 $indexStack[] = 0;
1187                         } elseif ( $iteratorStack[$level] === false ) {
1188                                 // Return accumulated value to parent
1189                                 // With tail recursion
1190                                 while ( $iteratorStack[$level] === false && $level > 0 ) {
1191                                         $outStack[$level - 1] .= $out;
1192                                         array_pop( $outStack );
1193                                         array_pop( $iteratorStack );
1194                                         array_pop( $indexStack );
1195                                         $level--;
1196                                 }
1197                         }
1198                 }
1199                 --$expansionDepth;
1200                 wfProfileOut( __METHOD__ );
1201                 return $outStack[0];
1202         }
1203
1204         /**
1205          * @param $sep
1206          * @param $flags
1207          * @return string
1208          */
1209         function implodeWithFlags( $sep, $flags /*, ... */ ) {
1210                 $args = array_slice( func_get_args(), 2 );
1211
1212                 $first = true;
1213                 $s = '';
1214                 foreach ( $args as $root ) {
1215                         if ( $root instanceof PPNode_DOM ) $root = $root->node;
1216                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1217                                 $root = array( $root );
1218                         }
1219                         foreach ( $root as $node ) {
1220                                 if ( $first ) {
1221                                         $first = false;
1222                                 } else {
1223                                         $s .= $sep;
1224                                 }
1225                                 $s .= $this->expand( $node, $flags );
1226                         }
1227                 }
1228                 return $s;
1229         }
1230
1231         /**
1232          * Implode with no flags specified
1233          * This previously called implodeWithFlags but has now been inlined to reduce stack depth
1234          *
1235          * @return string
1236          */
1237         function implode( $sep /*, ... */ ) {
1238                 $args = array_slice( func_get_args(), 1 );
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 );
1256                         }
1257                 }
1258                 return $s;
1259         }
1260
1261         /**
1262          * Makes an object that, when expand()ed, will be the same as one obtained
1263          * with implode()
1264          *
1265          * @return array
1266          */
1267         function virtualImplode( $sep /*, ... */ ) {
1268                 $args = array_slice( func_get_args(), 1 );
1269                 $out = array();
1270                 $first = true;
1271
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                                         $out[] = $sep;
1284                                 }
1285                                 $out[] = $node;
1286                         }
1287                 }
1288                 return $out;
1289         }
1290
1291         /**
1292          * Virtual implode with brackets
1293          * @return array
1294          */
1295         function virtualBracketedImplode( $start, $sep, $end /*, ... */ ) {
1296                 $args = array_slice( func_get_args(), 3 );
1297                 $out = array( $start );
1298                 $first = true;
1299
1300                 foreach ( $args as $root ) {
1301                         if ( $root instanceof PPNode_DOM ) {
1302                                 $root = $root->node;
1303                         }
1304                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1305                                 $root = array( $root );
1306                         }
1307                         foreach ( $root as $node ) {
1308                                 if ( $first ) {
1309                                         $first = false;
1310                                 } else {
1311                                         $out[] = $sep;
1312                                 }
1313                                 $out[] = $node;
1314                         }
1315                 }
1316                 $out[] = $end;
1317                 return $out;
1318         }
1319
1320         function __toString() {
1321                 return 'frame{}';
1322         }
1323
1324         function getPDBK( $level = false ) {
1325                 if ( $level === false ) {
1326                         return $this->title->getPrefixedDBkey();
1327                 } else {
1328                         return isset( $this->titleCache[$level] ) ? $this->titleCache[$level] : false;
1329                 }
1330         }
1331
1332         /**
1333          * @return array
1334          */
1335         function getArguments() {
1336                 return array();
1337         }
1338
1339         /**
1340          * @return array
1341          */
1342         function getNumberedArguments() {
1343                 return array();
1344         }
1345
1346         /**
1347          * @return array
1348          */
1349         function getNamedArguments() {
1350                 return array();
1351         }
1352
1353         /**
1354          * Returns true if there are no arguments in this frame
1355          *
1356          * @return bool
1357          */
1358         function isEmpty() {
1359                 return true;
1360         }
1361
1362         function getArgument( $name ) {
1363                 return false;
1364         }
1365
1366         /**
1367          * Returns true if the infinite loop check is OK, false if a loop is detected
1368          *
1369          * @return bool
1370          */
1371         function loopCheck( $title ) {
1372                 return !isset( $this->loopCheckHash[$title->getPrefixedDBkey()] );
1373         }
1374
1375         /**
1376          * Return true if the frame is a template frame
1377          *
1378          * @return bool
1379          */
1380         function isTemplate() {
1381                 return false;
1382         }
1383
1384         /**
1385          * Get a title of frame
1386          *
1387          * @return Title
1388          */
1389         function getTitle() {
1390                 return $this->title;
1391         }
1392 }
1393
1394 /**
1395  * Expansion frame with template arguments
1396  * @ingroup Parser
1397  */
1398 class PPTemplateFrame_DOM extends PPFrame_DOM {
1399         var $numberedArgs, $namedArgs;
1400
1401         /**
1402          * @var PPFrame_DOM
1403          */
1404         var $parent;
1405         var $numberedExpansionCache, $namedExpansionCache;
1406
1407         /**
1408          * @param $preprocessor
1409          * @param $parent PPFrame_DOM
1410          * @param $numberedArgs array
1411          * @param $namedArgs array
1412          * @param $title Title
1413          */
1414         function __construct( $preprocessor, $parent = false, $numberedArgs = array(), $namedArgs = array(), $title = false ) {
1415                 parent::__construct( $preprocessor );
1416
1417                 $this->parent = $parent;
1418                 $this->numberedArgs = $numberedArgs;
1419                 $this->namedArgs = $namedArgs;
1420                 $this->title = $title;
1421                 $pdbk = $title ? $title->getPrefixedDBkey() : false;
1422                 $this->titleCache = $parent->titleCache;
1423                 $this->titleCache[] = $pdbk;
1424                 $this->loopCheckHash = /*clone*/ $parent->loopCheckHash;
1425                 if ( $pdbk !== false ) {
1426                         $this->loopCheckHash[$pdbk] = true;
1427                 }
1428                 $this->depth = $parent->depth + 1;
1429                 $this->numberedExpansionCache = $this->namedExpansionCache = array();
1430         }
1431
1432         function __toString() {
1433                 $s = 'tplframe{';
1434                 $first = true;
1435                 $args = $this->numberedArgs + $this->namedArgs;
1436                 foreach ( $args as $name => $value ) {
1437                         if ( $first ) {
1438                                 $first = false;
1439                         } else {
1440                                 $s .= ', ';
1441                         }
1442                         $s .= "\"$name\":\"" .
1443                                 str_replace( '"', '\\"', $value->ownerDocument->saveXML( $value ) ) . '"';
1444                 }
1445                 $s .= '}';
1446                 return $s;
1447         }
1448
1449         /**
1450          * Returns true if there are no arguments in this frame
1451          *
1452          * @return bool
1453          */
1454         function isEmpty() {
1455                 return !count( $this->numberedArgs ) && !count( $this->namedArgs );
1456         }
1457
1458         function getArguments() {
1459                 $arguments = array();
1460                 foreach ( array_merge(
1461                                 array_keys($this->numberedArgs),
1462                                 array_keys($this->namedArgs)) as $key ) {
1463                         $arguments[$key] = $this->getArgument($key);
1464                 }
1465                 return $arguments;
1466         }
1467
1468         function getNumberedArguments() {
1469                 $arguments = array();
1470                 foreach ( array_keys($this->numberedArgs) as $key ) {
1471                         $arguments[$key] = $this->getArgument($key);
1472                 }
1473                 return $arguments;
1474         }
1475
1476         function getNamedArguments() {
1477                 $arguments = array();
1478                 foreach ( array_keys($this->namedArgs) as $key ) {
1479                         $arguments[$key] = $this->getArgument($key);
1480                 }
1481                 return $arguments;
1482         }
1483
1484         function getNumberedArgument( $index ) {
1485                 if ( !isset( $this->numberedArgs[$index] ) ) {
1486                         return false;
1487                 }
1488                 if ( !isset( $this->numberedExpansionCache[$index] ) ) {
1489                         # No trimming for unnamed arguments
1490                         $this->numberedExpansionCache[$index] = $this->parent->expand( $this->numberedArgs[$index], PPFrame::STRIP_COMMENTS );
1491                 }
1492                 return $this->numberedExpansionCache[$index];
1493         }
1494
1495         function getNamedArgument( $name ) {
1496                 if ( !isset( $this->namedArgs[$name] ) ) {
1497                         return false;
1498                 }
1499                 if ( !isset( $this->namedExpansionCache[$name] ) ) {
1500                         # Trim named arguments post-expand, for backwards compatibility
1501                         $this->namedExpansionCache[$name] = trim(
1502                                 $this->parent->expand( $this->namedArgs[$name], PPFrame::STRIP_COMMENTS ) );
1503                 }
1504                 return $this->namedExpansionCache[$name];
1505         }
1506
1507         function getArgument( $name ) {
1508                 $text = $this->getNumberedArgument( $name );
1509                 if ( $text === false ) {
1510                         $text = $this->getNamedArgument( $name );
1511                 }
1512                 return $text;
1513         }
1514
1515         /**
1516          * Return true if the frame is a template frame
1517          *
1518          * @return bool
1519          */
1520         function isTemplate() {
1521                 return true;
1522         }
1523 }
1524
1525 /**
1526  * Expansion frame with custom arguments
1527  * @ingroup Parser
1528  */
1529 class PPCustomFrame_DOM extends PPFrame_DOM {
1530         var $args;
1531
1532         function __construct( $preprocessor, $args ) {
1533                 parent::__construct( $preprocessor );
1534                 $this->args = $args;
1535         }
1536
1537         function __toString() {
1538                 $s = 'cstmframe{';
1539                 $first = true;
1540                 foreach ( $this->args as $name => $value ) {
1541                         if ( $first ) {
1542                                 $first = false;
1543                         } else {
1544                                 $s .= ', ';
1545                         }
1546                         $s .= "\"$name\":\"" .
1547                                 str_replace( '"', '\\"', $value->__toString() ) . '"';
1548                 }
1549                 $s .= '}';
1550                 return $s;
1551         }
1552
1553         /**
1554          * @return bool
1555          */
1556         function isEmpty() {
1557                 return !count( $this->args );
1558         }
1559
1560         function getArgument( $index ) {
1561                 if ( !isset( $this->args[$index] ) ) {
1562                         return false;
1563                 }
1564                 return $this->args[$index];
1565         }
1566
1567         function getArguments() {
1568                 return $this->args;
1569         }
1570 }
1571
1572 /**
1573  * @ingroup Parser
1574  */
1575 class PPNode_DOM implements PPNode {
1576
1577         /**
1578          * @var DOMElement
1579          */
1580         var $node;
1581         var $xpath;
1582
1583         function __construct( $node, $xpath = false ) {
1584                 $this->node = $node;
1585         }
1586
1587         /**
1588          * @return DOMXPath
1589          */
1590         function getXPath() {
1591                 if ( $this->xpath === null ) {
1592                         $this->xpath = new DOMXPath( $this->node->ownerDocument );
1593                 }
1594                 return $this->xpath;
1595         }
1596
1597         function __toString() {
1598                 if ( $this->node instanceof DOMNodeList ) {
1599                         $s = '';
1600                         foreach ( $this->node as $node ) {
1601                                 $s .= $node->ownerDocument->saveXML( $node );
1602                         }
1603                 } else {
1604                         $s = $this->node->ownerDocument->saveXML( $this->node );
1605                 }
1606                 return $s;
1607         }
1608
1609         /**
1610          * @return bool|PPNode_DOM
1611          */
1612         function getChildren() {
1613                 return $this->node->childNodes ? new self( $this->node->childNodes ) : false;
1614         }
1615
1616         /**
1617          * @return bool|PPNode_DOM
1618          */
1619         function getFirstChild() {
1620                 return $this->node->firstChild ? new self( $this->node->firstChild ) : false;
1621         }
1622
1623         /**
1624          * @return bool|PPNode_DOM
1625          */
1626         function getNextSibling() {
1627                 return $this->node->nextSibling ? new self( $this->node->nextSibling ) : false;
1628         }
1629
1630         /**
1631          * @param $type
1632          *
1633          * @return bool|PPNode_DOM
1634          */
1635         function getChildrenOfType( $type ) {
1636                 return new self( $this->getXPath()->query( $type, $this->node ) );
1637         }
1638
1639         /**
1640          * @return int
1641          */
1642         function getLength() {
1643                 if ( $this->node instanceof DOMNodeList ) {
1644                         return $this->node->length;
1645                 } else {
1646                         return false;
1647                 }
1648         }
1649
1650         /**
1651          * @param $i
1652          * @return bool|PPNode_DOM
1653          */
1654         function item( $i ) {
1655                 $item = $this->node->item( $i );
1656                 return $item ? new self( $item ) : false;
1657         }
1658
1659         /**
1660          * @return string
1661          */
1662         function getName() {
1663                 if ( $this->node instanceof DOMNodeList ) {
1664                         return '#nodelist';
1665                 } else {
1666                         return $this->node->nodeName;
1667                 }
1668         }
1669
1670         /**
1671          * Split a "<part>" node into an associative array containing:
1672          *  - name          PPNode name
1673          *  - index         String index
1674          *  - value         PPNode value
1675          *
1676          * @return array
1677          */
1678         function splitArg() {
1679                 $xpath = $this->getXPath();
1680                 $names = $xpath->query( 'name', $this->node );
1681                 $values = $xpath->query( 'value', $this->node );
1682                 if ( !$names->length || !$values->length ) {
1683                         throw new MWException( 'Invalid brace node passed to ' . __METHOD__ );
1684                 }
1685                 $name = $names->item( 0 );
1686                 $index = $name->getAttribute( 'index' );
1687                 return array(
1688                         'name' => new self( $name ),
1689                         'index' => $index,
1690                         'value' => new self( $values->item( 0 ) ) );
1691         }
1692
1693         /**
1694          * Split an "<ext>" node into an associative array containing name, attr, inner and close
1695          * All values in the resulting array are PPNodes. Inner and close are optional.
1696          *
1697          * @return array
1698          */
1699         function splitExt() {
1700                 $xpath = $this->getXPath();
1701                 $names = $xpath->query( 'name', $this->node );
1702                 $attrs = $xpath->query( 'attr', $this->node );
1703                 $inners = $xpath->query( 'inner', $this->node );
1704                 $closes = $xpath->query( 'close', $this->node );
1705                 if ( !$names->length || !$attrs->length ) {
1706                         throw new MWException( 'Invalid ext node passed to ' . __METHOD__ );
1707                 }
1708                 $parts = array(
1709                         'name' => new self( $names->item( 0 ) ),
1710                         'attr' => new self( $attrs->item( 0 ) ) );
1711                 if ( $inners->length ) {
1712                         $parts['inner'] = new self( $inners->item( 0 ) );
1713                 }
1714                 if ( $closes->length ) {
1715                         $parts['close'] = new self( $closes->item( 0 ) );
1716                 }
1717                 return $parts;
1718         }
1719
1720         /**
1721          * Split a "<h>" node
1722          * @return array
1723          */
1724         function splitHeading() {
1725                 if ( $this->getName() !== 'h' ) {
1726                         throw new MWException( 'Invalid h node passed to ' . __METHOD__ );
1727                 }
1728                 return array(
1729                         'i' => $this->node->getAttribute( 'i' ),
1730                         'level' => $this->node->getAttribute( 'level' ),
1731                         'contents' => $this->getChildren()
1732                 );
1733         }
1734 }