includes/parser/Preprocessor_DOM.php

   1 <?php
   2 /**
   3  * Preprocessor using PHP's dom extension
   4  *
   5  * @file
   6  * @ingroup Parser
   7  */
   8
   9 /**
  10  * @ingroup Parser
  11  */
  12 class Preprocessor_DOM implements Preprocessor {
  13
  14         /**
  15          * @var Parser
  16          */
  17         var $parser;
  18
  19         var $memoryLimit;
  20
  21         const CACHE_VERSION = 1;
  22
  23         function __construct( $parser ) {
  24                 $this->parser = $parser;
  25                 $mem = ini_get( 'memory_limit' );
  26                 $this->memoryLimit = false;
  27                 if ( strval( $mem ) !== '' && $mem != -1 ) {
  28                         if ( preg_match( '/^\d+$/', $mem ) ) {
  29                                 $this->memoryLimit = $mem;
  30                         } elseif ( preg_match( '/^(\d+)M$/i', $mem, $m ) ) {
  31                                 $this->memoryLimit = $m[1] * 1048576;
  32                         }
  33                 }
  34         }
  35
  36         /**
  37          * @return PPFrame_DOM
  38          */
  39         function newFrame() {
  40                 return new PPFrame_DOM( $this );
  41         }
  42
  43         /**
  44          * @param $args
  45          * @return PPCustomFrame_DOM
  46          */
  47         function newCustomFrame( $args ) {
  48                 return new PPCustomFrame_DOM( $this, $args );
  49         }
  50
  51         /**
  52          * @param $values
  53          * @return PPNode_DOM
  54          */
  55         function newPartNodeArray( $values ) {
  56                 //NOTE: DOM manipulation is slower than building & parsing XML! (or so Tim sais)
  57                 $xml = "<list>";
  58
  59                 foreach ( $values as $k => $val ) {
  60
  61                         if ( is_int( $k ) ) {
  62                                 $xml .= "<part><name index=\"$k\"/><value>" . htmlspecialchars( $val ) ."</value></part>";
  63                         } else {
  64                                 $xml .= "<part><name>" . htmlspecialchars( $k ) . "</name>=<value>" . htmlspecialchars( $val ) . "</value></part>";
  65                         }
  66                 }
  67
  68                 $xml .= "</list>";
  69
  70                 $dom = new DOMDocument();
  71                 $dom->loadXML( $xml );
  72                 $root = $dom->documentElement;
  73
  74                 $node = new PPNode_DOM( $root->childNodes );
  75                 return $node;
  76         }
  77
  78         /**
  79          * @throws MWException
  80          * @return bool
  81          */
  82         function memCheck() {
  83                 if ( $this->memoryLimit === false ) {
  84                         return;
  85                 }
  86                 $usage = memory_get_usage();
  87                 if ( $usage > $this->memoryLimit * 0.9 ) {
  88                         $limit = intval( $this->memoryLimit * 0.9 / 1048576 + 0.5 );
  89                         throw new MWException( "Preprocessor hit 90% memory limit ($limit MB)" );
  90                 }
  91                 return $usage <= $this->memoryLimit * 0.8;
  92         }
  93
  94         /**
  95          * Preprocess some wikitext and return the document tree.
  96          * This is the ghost of Parser::replace_variables().
  97          *
  98          * @param $text String: the text to parse
  99          * @param $flags Integer: bitwise combination of:
 100          *          Parser::PTD_FOR_INCLUSION    Handle <noinclude>/<includeonly> as if the text is being
 101          *                                     included. Default is to assume a direct page view.
 102          *
 103          * The generated DOM tree must depend only on the input text and the flags.
 104          * The DOM tree must be the same in OT_HTML and OT_WIKI mode, to avoid a regression of bug 4899.
 105          *
 106          * Any flag added to the $flags parameter here, or any other parameter liable to cause a
 107          * change in the DOM tree for a given text, must be passed through the section identifier
 108          * in the section edit link and thus back to extractSections().
 109          *
 110          * The output of this function is currently only cached in process memory, but a persistent
 111          * cache may be implemented at a later date which takes further advantage of these strict
 112          * dependency requirements.
 113          *
 114          * @return PPNode_DOM
 115          */
 116         function preprocessToObj( $text, $flags = 0 ) {
 117                 wfProfileIn( __METHOD__ );
 118                 global $wgMemc, $wgPreprocessorCacheThreshold;
 119
 120                 $xml = false;
 121                 $cacheable = ( $wgPreprocessorCacheThreshold !== false
 122                         && strlen( $text ) > $wgPreprocessorCacheThreshold );
 123                 if ( $cacheable ) {
 124                         wfProfileIn( __METHOD__.'-cacheable' );
 125
 126                         $cacheKey = wfMemcKey( 'preprocess-xml', md5($text), $flags );
 127                         $cacheValue = $wgMemc->get( $cacheKey );
 128                         if ( $cacheValue ) {
 129                                 $version = substr( $cacheValue, 0, 8 );
 130                                 if ( intval( $version ) == self::CACHE_VERSION ) {
 131                                         $xml = substr( $cacheValue, 8 );
 132                                         // From the cache
 133                                         wfDebugLog( "Preprocessor", "Loaded preprocessor XML from memcached (key $cacheKey)" );
 134                                 }
 135                         }
 136                 }
 137                 if ( $xml === false ) {
 138                         if ( $cacheable ) {
 139                                 wfProfileIn( __METHOD__.'-cache-miss' );
 140                                 $xml = $this->preprocessToXml( $text, $flags );
 141                                 $cacheValue = sprintf( "%08d", self::CACHE_VERSION ) . $xml;
 142                                 $wgMemc->set( $cacheKey, $cacheValue, 86400 );
 143                                 wfProfileOut( __METHOD__.'-cache-miss' );
 144                                 wfDebugLog( "Preprocessor", "Saved preprocessor XML to memcached (key $cacheKey)" );
 145                         } else {
 146                                 $xml = $this->preprocessToXml( $text, $flags );
 147                         }
 148
 149                 }
 150                 wfProfileIn( __METHOD__.'-loadXML' );
 151                 $dom = new DOMDocument;
 152                 wfSuppressWarnings();
 153                 $result = $dom->loadXML( $xml );
 154                 wfRestoreWarnings();
 155                 if ( !$result ) {
 156                         // Try running the XML through UtfNormal to get rid of invalid characters
 157                         $xml = UtfNormal::cleanUp( $xml );
 158                         $result = $dom->loadXML( $xml );
 159                         if ( !$result ) {
 160                                 throw new MWException( __METHOD__.' generated invalid XML' );
 161                         }
 162                 }
 163                 $obj = new PPNode_DOM( $dom->documentElement );
 164                 wfProfileOut( __METHOD__.'-loadXML' );
 165                 if ( $cacheable ) {
 166                         wfProfileOut( __METHOD__.'-cacheable' );
 167                 }
 168                 wfProfileOut( __METHOD__ );
 169                 return $obj;
 170         }
 171
 172         /**
 173          * @param $text string
 174          * @param $flags int
 175          * @return string
 176          */
 177         function preprocessToXml( $text, $flags = 0 ) {
 178                 wfProfileIn( __METHOD__ );
 179                 $rules = array(
 180                         '{' => array(
 181                                 'end' => '}',
 182                                 'names' => array(
 183                                         2 => 'template',
 184                                         3 => 'tplarg',
 185                                 ),
 186                                 'min' => 2,
 187                                 'max' => 3,
 188                         ),
 189                         '[' => array(
 190                                 'end' => ']',
 191                                 'names' => array( 2 => null ),
 192                                 'min' => 2,
 193                                 'max' => 2,
 194                         )
 195                 );
 196
 197                 $forInclusion = $flags & Parser::PTD_FOR_INCLUSION;
 198
 199                 $xmlishElements = $this->parser->getStripList();
 200                 $enableOnlyinclude = false;
 201                 if ( $forInclusion ) {
 202                         $ignoredTags = array( 'includeonly', '/includeonly' );
 203                         $ignoredElements = array( 'noinclude' );
 204                         $xmlishElements[] = 'noinclude';
 205                         if ( strpos( $text, '<onlyinclude>' ) !== false && strpos( $text, '</onlyinclude>' ) !== false ) {
 206                                 $enableOnlyinclude = true;
 207                         }
 208                 } else {
 209                         $ignoredTags = array( 'noinclude', '/noinclude', 'onlyinclude', '/onlyinclude' );
 210                         $ignoredElements = array( 'includeonly' );
 211                         $xmlishElements[] = 'includeonly';
 212                 }
 213                 $xmlishRegex = implode( '|', array_merge( $xmlishElements, $ignoredTags ) );
 214
 215                 // Use "A" modifier (anchored) instead of "^", because ^ doesn't work with an offset
 216                 $elementsRegex = "~($xmlishRegex)(?:\s|\/>|>)|(!--)~iA";
 217
 218                 $stack = new PPDStack;
 219
 220                 $searchBase = "[{<\n"; #}
 221                 $revText = strrev( $text ); // For fast reverse searches
 222
 223                 $i = 0;                     # Input pointer, starts out pointing to a pseudo-newline before the start
 224                 $accum =& $stack->getAccum();   # Current accumulator
 225                 $accum = '<root>';
 226                 $findEquals = false;            # True to find equals signs in arguments
 227                 $findPipe = false;              # True to take notice of pipe characters
 228                 $headingIndex = 1;
 229                 $inHeading = false;        # True if $i is inside a possible heading
 230                 $noMoreGT = false;         # True if there are no more greater-than (>) signs right of $i
 231                 $findOnlyinclude = $enableOnlyinclude; # True to ignore all input up to the next <onlyinclude>
 232                 $fakeLineStart = true;     # Do a line-start run without outputting an LF character
 233
 234                 while ( true ) {
 235                         //$this->memCheck();
 236
 237                         if ( $findOnlyinclude ) {
 238                                 // Ignore all input up to the next <onlyinclude>
 239                                 $startPos = strpos( $text, '<onlyinclude>', $i );
 240                                 if ( $startPos === false ) {
 241                                         // Ignored section runs to the end
 242                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i ) ) . '</ignore>';
 243                                         break;
 244                                 }
 245                                 $tagEndPos = $startPos + strlen( '<onlyinclude>' ); // past-the-end
 246                                 $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i, $tagEndPos - $i ) ) . '</ignore>';
 247                                 $i = $tagEndPos;
 248                                 $findOnlyinclude = false;
 249                         }
 250
 251                         if ( $fakeLineStart ) {
 252                                 $found = 'line-start';
 253                                 $curChar = '';
 254                         } else {
 255                                 # Find next opening brace, closing brace or pipe
 256                                 $search = $searchBase;
 257                                 if ( $stack->top === false ) {
 258                                         $currentClosing = '';
 259                                 } else {
 260                                         $currentClosing = $stack->top->close;
 261                                         $search .= $currentClosing;
 262                                 }
 263                                 if ( $findPipe ) {
 264                                         $search .= '|';
 265                                 }
 266                                 if ( $findEquals ) {
 267                                         // First equals will be for the template
 268                                         $search .= '=';
 269                                 }
 270                                 $rule = null;
 271                                 # Output literal section, advance input counter
 272                                 $literalLength = strcspn( $text, $search, $i );
 273                                 if ( $literalLength > 0 ) {
 274                                         $accum .= htmlspecialchars( substr( $text, $i, $literalLength ) );
 275                                         $i += $literalLength;
 276                                 }
 277                                 if ( $i >= strlen( $text ) ) {
 278                                         if ( $currentClosing == "\n" ) {
 279                                                 // Do a past-the-end run to finish off the heading
 280                                                 $curChar = '';
 281                                                 $found = 'line-end';
 282                                         } else {
 283                                                 # All done
 284                                                 break;
 285                                         }
 286                                 } else {
 287                                         $curChar = $text[$i];
 288                                         if ( $curChar == '|' ) {
 289                                                 $found = 'pipe';
 290                                         } elseif ( $curChar == '=' ) {
 291                                                 $found = 'equals';
 292                                         } elseif ( $curChar == '<' ) {
 293                                                 $found = 'angle';
 294                                         } elseif ( $curChar == "\n" ) {
 295                                                 if ( $inHeading ) {
 296                                                         $found = 'line-end';
 297                                                 } else {
 298                                                         $found = 'line-start';
 299                                                 }
 300                                         } elseif ( $curChar == $currentClosing ) {
 301                                                 $found = 'close';
 302                                         } elseif ( isset( $rules[$curChar] ) ) {
 303                                                 $found = 'open';
 304                                                 $rule = $rules[$curChar];
 305                                         } else {
 306                                                 # Some versions of PHP have a strcspn which stops on null characters
 307                                                 # Ignore and continue
 308                                                 ++$i;
 309                                                 continue;
 310                                         }
 311                                 }
 312                         }
 313
 314                         if ( $found == 'angle' ) {
 315                                 $matches = false;
 316                                 // Handle </onlyinclude>
 317                                 if ( $enableOnlyinclude && substr( $text, $i, strlen( '</onlyinclude>' ) ) == '</onlyinclude>' ) {
 318                                         $findOnlyinclude = true;
 319                                         continue;
 320                                 }
 321
 322                                 // Determine element name
 323                                 if ( !preg_match( $elementsRegex, $text, $matches, 0, $i + 1 ) ) {
 324                                         // Element name missing or not listed
 325                                         $accum .= '&lt;';
 326                                         ++$i;
 327                                         continue;
 328                                 }
 329                                 // Handle comments
 330                                 if ( isset( $matches[2] ) && $matches[2] == '!--' ) {
 331                                         // To avoid leaving blank lines, when a comment is both preceded
 332                                         // and followed by a newline (ignoring spaces), trim leading and
 333                                         // trailing spaces and one of the newlines.
 334
 335                                         // Find the end
 336                                         $endPos = strpos( $text, '-->', $i + 4 );
 337                                         if ( $endPos === false ) {
 338                                                 // Unclosed comment in input, runs to end
 339                                                 $inner = substr( $text, $i );
 340                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 341                                                 $i = strlen( $text );
 342                                         } else {
 343                                                 // Search backwards for leading whitespace
 344                                                 $wsStart = $i ? ( $i - strspn( $revText, ' ', strlen( $text ) - $i ) ) : 0;
 345                                                 // Search forwards for trailing whitespace
 346                                                 // $wsEnd will be the position of the last space (or the '>' if there's none)
 347                                                 $wsEnd = $endPos + 2 + strspn( $text, ' ', $endPos + 3 );
 348                                                 // Eat the line if possible
 349                                                 // TODO: This could theoretically be done if $wsStart == 0, i.e. for comments at
 350                                                 // the overall start. That's not how Sanitizer::removeHTMLcomments() did it, but
 351                                                 // it's a possible beneficial b/c break.
 352                                                 if ( $wsStart > 0 && substr( $text, $wsStart - 1, 1 ) == "\n"
 353                                                         && substr( $text, $wsEnd + 1, 1 ) == "\n" )
 354                                                 {
 355                                                         $startPos = $wsStart;
 356                                                         $endPos = $wsEnd + 1;
 357                                                         // Remove leading whitespace from the end of the accumulator
 358                                                         // Sanity check first though
 359                                                         $wsLength = $i - $wsStart;
 360                                                         if ( $wsLength > 0 && substr( $accum, -$wsLength ) === str_repeat( ' ', $wsLength ) ) {
 361                                                                 $accum = substr( $accum, 0, -$wsLength );
 362                                                         }
 363                                                         // Do a line-start run next time to look for headings after the comment
 364                                                         $fakeLineStart = true;
 365                                                 } else {
 366                                                         // No line to eat, just take the comment itself
 367                                                         $startPos = $i;
 368                                                         $endPos += 2;
 369                                                 }
 370
 371                                                 if ( $stack->top ) {
 372                                                         $part = $stack->top->getCurrentPart();
 373                                                         if ( ! (isset( $part->commentEnd ) && $part->commentEnd == $wsStart - 1 )) {
 374                                                                 $part->visualEnd = $wsStart;
 375                                                         }
 376                                                         // Else comments abutting, no change in visual end
 377                                                         $part->commentEnd = $endPos;
 378                                                 }
 379                                                 $i = $endPos + 1;
 380                                                 $inner = substr( $text, $startPos, $endPos - $startPos + 1 );
 381                                                 $accum .= '<comment>' . htmlspecialchars( $inner ) . '</comment>';
 382                                         }
 383                                         continue;
 384                                 }
 385                                 $name = $matches[1];
 386                                 $lowerName = strtolower( $name );
 387                                 $attrStart = $i + strlen( $name ) + 1;
 388
 389                                 // Find end of tag
 390                                 $tagEndPos = $noMoreGT ? false : strpos( $text, '>', $attrStart );
 391                                 if ( $tagEndPos === false ) {
 392                                         // Infinite backtrack
 393                                         // Disable tag search to prevent worst-case O(N^2) performance
 394                                         $noMoreGT = true;
 395                                         $accum .= '&lt;';
 396                                         ++$i;
 397                                         continue;
 398                                 }
 399
 400                                 // Handle ignored tags
 401                                 if ( in_array( $lowerName, $ignoredTags ) ) {
 402                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $i, $tagEndPos - $i + 1 ) ) . '</ignore>';
 403                                         $i = $tagEndPos + 1;
 404                                         continue;
 405                                 }
 406
 407                                 $tagStartPos = $i;
 408                                 if ( $text[$tagEndPos-1] == '/' ) {
 409                                         $attrEnd = $tagEndPos - 1;
 410                                         $inner = null;
 411                                         $i = $tagEndPos + 1;
 412                                         $close = '';
 413                                 } else {
 414                                         $attrEnd = $tagEndPos;
 415                                         // Find closing tag
 416                                         if ( preg_match( "/<\/" . preg_quote( $name, '/' ) . "\s*>/i",
 417                                                         $text, $matches, PREG_OFFSET_CAPTURE, $tagEndPos + 1 ) )
 418                                         {
 419                                                 $inner = substr( $text, $tagEndPos + 1, $matches[0][1] - $tagEndPos - 1 );
 420                                                 $i = $matches[0][1] + strlen( $matches[0][0] );
 421                                                 $close = '<close>' . htmlspecialchars( $matches[0][0] ) . '</close>';
 422                                         } else {
 423                                                 // No end tag -- let it run out to the end of the text.
 424                                                 $inner = substr( $text, $tagEndPos + 1 );
 425                                                 $i = strlen( $text );
 426                                                 $close = '';
 427                                         }
 428                                 }
 429                                 // <includeonly> and <noinclude> just become <ignore> tags
 430                                 if ( in_array( $lowerName, $ignoredElements ) ) {
 431                                         $accum .= '<ignore>' . htmlspecialchars( substr( $text, $tagStartPos, $i - $tagStartPos ) )
 432                                                 . '</ignore>';
 433                                         continue;
 434                                 }
 435
 436                                 $accum .= '<ext>';
 437                                 if ( $attrEnd <= $attrStart ) {
 438                                         $attr = '';
 439                                 } else {
 440                                         $attr = substr( $text, $attrStart, $attrEnd - $attrStart );
 441                                 }
 442                                 $accum .= '<name>' . htmlspecialchars( $name ) . '</name>' .
 443                                         // Note that the attr element contains the whitespace between name and attribute,
 444                                         // this is necessary for precise reconstruction during pre-save transform.
 445                                         '<attr>' . htmlspecialchars( $attr ) . '</attr>';
 446                                 if ( $inner !== null ) {
 447                                         $accum .= '<inner>' . htmlspecialchars( $inner ) . '</inner>';
 448                                 }
 449                                 $accum .= $close . '</ext>';
 450                         } elseif ( $found == 'line-start' ) {
 451                                 // Is this the start of a heading?
 452                                 // Line break belongs before the heading element in any case
 453                                 if ( $fakeLineStart ) {
 454                                         $fakeLineStart = false;
 455                                 } else {
 456                                         $accum .= $curChar;
 457                                         $i++;
 458                                 }
 459
 460                                 $count = strspn( $text, '=', $i, 6 );
 461                                 if ( $count == 1 && $findEquals ) {
 462                                         // DWIM: This looks kind of like a name/value separator
 463                                         // Let's let the equals handler have it and break the potential heading
 464                                         // This is heuristic, but AFAICT the methods for completely correct disambiguation are very complex.
 465                                 } elseif ( $count > 0 ) {
 466                                         $piece = array(
 467                                                 'open' => "\n",
 468                                                 'close' => "\n",
 469                                                 'parts' => array( new PPDPart( str_repeat( '=', $count ) ) ),
 470                                                 'startPos' => $i,
 471                                                 'count' => $count );
 472                                         $stack->push( $piece );
 473                                         $accum =& $stack->getAccum();
 474                                         $flags = $stack->getFlags();
 475                                         extract( $flags );
 476                                         $i += $count;
 477                                 }
 478                         } elseif ( $found == 'line-end' ) {
 479                                 $piece = $stack->top;
 480                                 // A heading must be open, otherwise \n wouldn't have been in the search list
 481                                 assert( $piece->open == "\n" );
 482                                 $part = $piece->getCurrentPart();
 483                                 // Search back through the input to see if it has a proper close
 484                                 // Do this using the reversed string since the other solutions (end anchor, etc.) are inefficient
 485                                 $wsLength = strspn( $revText, " \t", strlen( $text ) - $i );
 486                                 $searchStart = $i - $wsLength;
 487                                 if ( isset( $part->commentEnd ) && $searchStart - 1 == $part->commentEnd ) {
 488                                         // Comment found at line end
 489                                         // Search for equals signs before the comment
 490                                         $searchStart = $part->visualEnd;
 491                                         $searchStart -= strspn( $revText, " \t", strlen( $text ) - $searchStart );
 492                                 }
 493                                 $count = $piece->count;
 494                                 $equalsLength = strspn( $revText, '=', strlen( $text ) - $searchStart );
 495                                 if ( $equalsLength > 0 ) {
 496                                         if ( $searchStart - $equalsLength == $piece->startPos ) {
 497                                                 // This is just a single string of equals signs on its own line
 498                                                 // Replicate the doHeadings behaviour /={count}(.+)={count}/
 499                                                 // First find out how many equals signs there really are (don't stop at 6)
 500                                                 $count = $equalsLength;
 501                                                 if ( $count < 3 ) {
 502                                                         $count = 0;
 503                                                 } else {
 504                                                         $count = min( 6, intval( ( $count - 1 ) / 2 ) );
 505                                                 }
 506                                         } else {
 507                                                 $count = min( $equalsLength, $count );
 508                                         }
 509                                         if ( $count > 0 ) {
 510                                                 // Normal match, output <h>
 511                                                 $element = "<h level=\"$count\" i=\"$headingIndex\">$accum</h>";
 512                                                 $headingIndex++;
 513                                         } else {
 514                                                 // Single equals sign on its own line, count=0
 515                                                 $element = $accum;
 516                                         }
 517                                 } else {
 518                                         // No match, no <h>, just pass down the inner text
 519                                         $element = $accum;
 520                                 }
 521                                 // Unwind the stack
 522                                 $stack->pop();
 523                                 $accum =& $stack->getAccum();
 524                                 $flags = $stack->getFlags();
 525                                 extract( $flags );
 526
 527                                 // Append the result to the enclosing accumulator
 528                                 $accum .= $element;
 529                                 // Note that we do NOT increment the input pointer.
 530                                 // This is because the closing linebreak could be the opening linebreak of
 531                                 // another heading. Infinite loops are avoided because the next iteration MUST
 532                                 // hit the heading open case above, which unconditionally increments the
 533                                 // input pointer.
 534                         } elseif ( $found == 'open' ) {
 535                                 # count opening brace characters
 536                                 $count = strspn( $text, $curChar, $i );
 537
 538                                 # we need to add to stack only if opening brace count is enough for one of the rules
 539                                 if ( $count >= $rule['min'] ) {
 540                                         # Add it to the stack
 541                                         $piece = array(
 542                                                 'open' => $curChar,
 543                                                 'close' => $rule['end'],
 544                                                 'count' => $count,
 545                                                 'lineStart' => ($i == 0 || $text[$i-1] == "\n"),
 546                                         );
 547
 548                                         $stack->push( $piece );
 549                                         $accum =& $stack->getAccum();
 550                                         $flags = $stack->getFlags();
 551                                         extract( $flags );
 552                                 } else {
 553                                         # Add literal brace(s)
 554                                         $accum .= htmlspecialchars( str_repeat( $curChar, $count ) );
 555                                 }
 556                                 $i += $count;
 557                         } elseif ( $found == 'close' ) {
 558                                 $piece = $stack->top;
 559                                 # lets check if there are enough characters for closing brace
 560                                 $maxCount = $piece->count;
 561                                 $count = strspn( $text, $curChar, $i, $maxCount );
 562
 563                                 # check for maximum matching characters (if there are 5 closing
 564                                 # characters, we will probably need only 3 - depending on the rules)
 565                                 $rule = $rules[$piece->open];
 566                                 if ( $count > $rule['max'] ) {
 567                                         # The specified maximum exists in the callback array, unless the caller
 568                                         # has made an error
 569                                         $matchingCount = $rule['max'];
 570                                 } else {
 571                                         # Count is less than the maximum
 572                                         # Skip any gaps in the callback array to find the true largest match
 573                                         # Need to use array_key_exists not isset because the callback can be null
 574                                         $matchingCount = $count;
 575                                         while ( $matchingCount > 0 && !array_key_exists( $matchingCount, $rule['names'] ) ) {
 576                                                 --$matchingCount;
 577                                         }
 578                                 }
 579
 580                                 if ( $matchingCount <= 0 ) {
 581                                         # No matching element found in callback array
 582                                         # Output a literal closing brace and continue
 583                                         $accum .= htmlspecialchars( str_repeat( $curChar, $count ) );
 584                                         $i += $count;
 585                                         continue;
 586                                 }
 587                                 $name = $rule['names'][$matchingCount];
 588                                 if ( $name === null ) {
 589                                         // No element, just literal text
 590                                         $element = $piece->breakSyntax( $matchingCount ) . str_repeat( $rule['end'], $matchingCount );
 591                                 } else {
 592                                         # Create XML element
 593                                         # Note: $parts is already XML, does not need to be encoded further
 594                                         $parts = $piece->parts;
 595                                         $title = $parts[0]->out;
 596                                         unset( $parts[0] );
 597
 598                                         # The invocation is at the start of the line if lineStart is set in
 599                                         # the stack, and all opening brackets are used up.
 600                                         if ( $maxCount == $matchingCount && !empty( $piece->lineStart ) ) {
 601                                                 $attr = ' lineStart="1"';
 602                                         } else {
 603                                                 $attr = '';
 604                                         }
 605
 606                                         $element = "<$name$attr>";
 607                                         $element .= "<title>$title</title>";
 608                                         $argIndex = 1;
 609                                         foreach ( $parts as $part ) {
 610                                                 if ( isset( $part->eqpos ) ) {
 611                                                         $argName = substr( $part->out, 0, $part->eqpos );
 612                                                         $argValue = substr( $part->out, $part->eqpos + 1 );
 613                                                         $element .= "<part><name>$argName</name>=<value>$argValue</value></part>";
 614                                                 } else {
 615                                                         $element .= "<part><name index=\"$argIndex\" /><value>{$part->out}</value></part>";
 616                                                         $argIndex++;
 617                                                 }
 618                                         }
 619                                         $element .= "</$name>";
 620                                 }
 621
 622                                 # Advance input pointer
 623                                 $i += $matchingCount;
 624
 625                                 # Unwind the stack
 626                                 $stack->pop();
 627                                 $accum =& $stack->getAccum();
 628
 629                                 # Re-add the old stack element if it still has unmatched opening characters remaining
 630                                 if ( $matchingCount < $piece->count ) {
 631                                         $piece->parts = array( new PPDPart );
 632                                         $piece->count -= $matchingCount;
 633                                         # do we still qualify for any callback with remaining count?
 634                                         $names = $rules[$piece->open]['names'];
 635                                         $skippedBraces = 0;
 636                                         $enclosingAccum =& $accum;
 637                                         while ( $piece->count ) {
 638                                                 if ( array_key_exists( $piece->count, $names ) ) {
 639                                                         $stack->push( $piece );
 640                                                         $accum =& $stack->getAccum();
 641                                                         break;
 642                                                 }
 643                                                 --$piece->count;
 644                                                 $skippedBraces ++;
 645                                         }
 646                                         $enclosingAccum .= str_repeat( $piece->open, $skippedBraces );
 647                                 }
 648                                 $flags = $stack->getFlags();
 649                                 extract( $flags );
 650
 651                                 # Add XML element to the enclosing accumulator
 652                                 $accum .= $element;
 653                         } elseif ( $found == 'pipe' ) {
 654                                 $findEquals = true; // shortcut for getFlags()
 655                                 $stack->addPart();
 656                                 $accum =& $stack->getAccum();
 657                                 ++$i;
 658                         } elseif ( $found == 'equals' ) {
 659                                 $findEquals = false; // shortcut for getFlags()
 660                                 $stack->getCurrentPart()->eqpos = strlen( $accum );
 661                                 $accum .= '=';
 662                                 ++$i;
 663                         }
 664                 }
 665
 666                 # Output any remaining unclosed brackets
 667                 foreach ( $stack->stack as $piece ) {
 668                         $stack->rootAccum .= $piece->breakSyntax();
 669                 }
 670                 $stack->rootAccum .= '</root>';
 671                 $xml = $stack->rootAccum;
 672
 673                 wfProfileOut( __METHOD__ );
 674
 675                 return $xml;
 676         }
 677 }
 678
 679 /**
 680  * Stack class to help Preprocessor::preprocessToObj()
 681  * @ingroup Parser
 682  */
 683 class PPDStack {
 684         var $stack, $rootAccum;
 685
 686         /**
 687          * @var PPDStack
 688          */
 689         var $top;
 690         var $out;
 691         var $elementClass = 'PPDStackElement';
 692
 693         static $false = false;
 694
 695         function __construct() {
 696                 $this->stack = array();
 697                 $this->top = false;
 698                 $this->rootAccum = '';
 699                 $this->accum =& $this->rootAccum;
 700         }
 701
 702         /**
 703          * @return int
 704          */
 705         function count() {
 706                 return count( $this->stack );
 707         }
 708
 709         function &getAccum() {
 710                 return $this->accum;
 711         }
 712
 713         function getCurrentPart() {
 714                 if ( $this->top === false ) {
 715                         return false;
 716                 } else {
 717                         return $this->top->getCurrentPart();
 718                 }
 719         }
 720
 721         function push( $data ) {
 722                 if ( $data instanceof $this->elementClass ) {
 723                         $this->stack[] = $data;
 724                 } else {
 725                         $class = $this->elementClass;
 726                         $this->stack[] = new $class( $data );
 727                 }
 728                 $this->top = $this->stack[ count( $this->stack ) - 1 ];
 729                 $this->accum =& $this->top->getAccum();
 730         }
 731
 732         function pop() {
 733                 if ( !count( $this->stack ) ) {
 734                         throw new MWException( __METHOD__.': no elements remaining' );
 735                 }
 736                 $temp = array_pop( $this->stack );
 737
 738                 if ( count( $this->stack ) ) {
 739                         $this->top = $this->stack[ count( $this->stack ) - 1 ];
 740                         $this->accum =& $this->top->getAccum();
 741                 } else {
 742                         $this->top = self::$false;
 743                         $this->accum =& $this->rootAccum;
 744                 }
 745                 return $temp;
 746         }
 747
 748         function addPart( $s = '' ) {
 749                 $this->top->addPart( $s );
 750                 $this->accum =& $this->top->getAccum();
 751         }
 752
 753         /**
 754          * @return array
 755          */
 756         function getFlags() {
 757                 if ( !count( $this->stack ) ) {
 758                         return array(
 759                                 'findEquals' => false,
 760                                 'findPipe' => false,
 761                                 'inHeading' => false,
 762                         );
 763                 } else {
 764                         return $this->top->getFlags();
 765                 }
 766         }
 767 }
 768
 769 /**
 770  * @ingroup Parser
 771  */
 772 class PPDStackElement {
 773         var $open,                      // Opening character (\n for heading)
 774                 $close,             // Matching closing character
 775                 $count,             // Number of opening characters found (number of "=" for heading)
 776                 $parts,             // Array of PPDPart objects describing pipe-separated parts.
 777                 $lineStart;         // True if the open char appeared at the start of the input line. Not set for headings.
 778
 779         var $partClass = 'PPDPart';
 780
 781         function __construct( $data = array() ) {
 782                 $class = $this->partClass;
 783                 $this->parts = array( new $class );
 784
 785                 foreach ( $data as $name => $value ) {
 786                         $this->$name = $value;
 787                 }
 788         }
 789
 790         function &getAccum() {
 791                 return $this->parts[count($this->parts) - 1]->out;
 792         }
 793
 794         function addPart( $s = '' ) {
 795                 $class = $this->partClass;
 796                 $this->parts[] = new $class( $s );
 797         }
 798
 799         function getCurrentPart() {
 800                 return $this->parts[count($this->parts) - 1];
 801         }
 802
 803         /**
 804          * @return array
 805          */
 806         function getFlags() {
 807                 $partCount = count( $this->parts );
 808                 $findPipe = $this->open != "\n" && $this->open != '[';
 809                 return array(
 810                         'findPipe' => $findPipe,
 811                         'findEquals' => $findPipe && $partCount > 1 && !isset( $this->parts[$partCount - 1]->eqpos ),
 812                         'inHeading' => $this->open == "\n",
 813                 );
 814         }
 815
 816         /**
 817          * Get the output string that would result if the close is not found.
 818          *
 819          * @return string
 820          */
 821         function breakSyntax( $openingCount = false ) {
 822                 if ( $this->open == "\n" ) {
 823                         $s = $this->parts[0]->out;
 824                 } else {
 825                         if ( $openingCount === false ) {
 826                                 $openingCount = $this->count;
 827                         }
 828                         $s = str_repeat( $this->open, $openingCount );
 829                         $first = true;
 830                         foreach ( $this->parts as $part ) {
 831                                 if ( $first ) {
 832                                         $first = false;
 833                                 } else {
 834                                         $s .= '|';
 835                                 }
 836                                 $s .= $part->out;
 837                         }
 838                 }
 839                 return $s;
 840         }
 841 }
 842
 843 /**
 844  * @ingroup Parser
 845  */
 846 class PPDPart {
 847         var $out; // Output accumulator string
 848
 849         // Optional member variables:
 850         //   eqpos        Position of equals sign in output accumulator
 851         //   commentEnd   Past-the-end input pointer for the last comment encountered
 852         //   visualEnd    Past-the-end input pointer for the end of the accumulator minus comments
 853
 854         function __construct( $out = '' ) {
 855                 $this->out = $out;
 856         }
 857 }
 858
 859 /**
 860  * An expansion frame, used as a context to expand the result of preprocessToObj()
 861  * @ingroup Parser
 862  */
 863 class PPFrame_DOM implements PPFrame {
 864
 865         /**
 866          * @var Preprocessor
 867          */
 868         var $preprocessor;
 869
 870         /**
 871          * @var Parser
 872          */
 873         var $parser;
 874
 875         /**
 876          * @var Title
 877          */
 878         var $title;
 879         var $titleCache;
 880
 881         /**
 882          * Hashtable listing templates which are disallowed for expansion in this frame,
 883          * having been encountered previously in parent frames.
 884          */
 885         var $loopCheckHash;
 886
 887         /**
 888          * Recursion depth of this frame, top = 0
 889          * Note that this is NOT the same as expansion depth in expand()
 890          */
 891         var $depth;
 892
 893
 894         /**
 895          * Construct a new preprocessor frame.
 896          * @param $preprocessor Preprocessor The parent preprocessor
 897          */
 898         function __construct( $preprocessor ) {
 899                 $this->preprocessor = $preprocessor;
 900                 $this->parser = $preprocessor->parser;
 901                 $this->title = $this->parser->mTitle;
 902                 $this->titleCache = array( $this->title ? $this->title->getPrefixedDBkey() : false );
 903                 $this->loopCheckHash = array();
 904                 $this->depth = 0;
 905         }
 906
 907         /**
 908          * Create a new child frame
 909          * $args is optionally a multi-root PPNode or array containing the template arguments
 910          *
 911          * @return PPTemplateFrame_DOM
 912          */
 913         function newChild( $args = false, $title = false ) {
 914                 $namedArgs = array();
 915                 $numberedArgs = array();
 916                 if ( $title === false ) {
 917                         $title = $this->title;
 918                 }
 919                 if ( $args !== false ) {
 920                         $xpath = false;
 921                         if ( $args instanceof PPNode ) {
 922                                 $args = $args->node;
 923                         }
 924                         foreach ( $args as $arg ) {
 925                                 if ( !$xpath ) {
 926                                         $xpath = new DOMXPath( $arg->ownerDocument );
 927                                 }
 928
 929                                 $nameNodes = $xpath->query( 'name', $arg );
 930                                 $value = $xpath->query( 'value', $arg );
 931                                 if ( $nameNodes->item( 0 )->hasAttributes() ) {
 932                                         // Numbered parameter
 933                                         $index = $nameNodes->item( 0 )->attributes->getNamedItem( 'index' )->textContent;
 934                                         $numberedArgs[$index] = $value->item( 0 );
 935                                         unset( $namedArgs[$index] );
 936                                 } else {
 937                                         // Named parameter
 938                                         $name = trim( $this->expand( $nameNodes->item( 0 ), PPFrame::STRIP_COMMENTS ) );
 939                                         $namedArgs[$name] = $value->item( 0 );
 940                                         unset( $numberedArgs[$name] );
 941                                 }
 942                         }
 943                 }
 944                 return new PPTemplateFrame_DOM( $this->preprocessor, $this, $numberedArgs, $namedArgs, $title );
 945         }
 946
 947         /**
 948          * @throws MWException
 949          * @param $root
 950          * @param $flags int
 951          * @return string
 952          */
 953         function expand( $root, $flags = 0 ) {
 954                 static $expansionDepth = 0;
 955                 if ( is_string( $root ) ) {
 956                         return $root;
 957                 }
 958
 959                 if ( ++$this->parser->mPPNodeCount > $this->parser->mOptions->getMaxPPNodeCount() )
 960                 {
 961                         return '<span class="error">Node-count limit exceeded</span>';
 962                 }
 963
 964                 if ( $expansionDepth > $this->parser->mOptions->getMaxPPExpandDepth() ) {
 965                         return '<span class="error">Expansion depth limit exceeded</span>';
 966                 }
 967                 wfProfileIn( __METHOD__ );
 968                 ++$expansionDepth;
 969
 970                 if ( $root instanceof PPNode_DOM ) {
 971                         $root = $root->node;
 972                 }
 973                 if ( $root instanceof DOMDocument ) {
 974                         $root = $root->documentElement;
 975                 }
 976
 977                 $outStack = array( '', '' );
 978                 $iteratorStack = array( false, $root );
 979                 $indexStack = array( 0, 0 );
 980
 981                 while ( count( $iteratorStack ) > 1 ) {
 982                         $level = count( $outStack ) - 1;
 983                         $iteratorNode =& $iteratorStack[ $level ];
 984                         $out =& $outStack[$level];
 985                         $index =& $indexStack[$level];
 986
 987                         if ( $iteratorNode instanceof PPNode_DOM ) $iteratorNode = $iteratorNode->node;
 988
 989                         if ( is_array( $iteratorNode ) ) {
 990                                 if ( $index >= count( $iteratorNode ) ) {
 991                                         // All done with this iterator
 992                                         $iteratorStack[$level] = false;
 993                                         $contextNode = false;
 994                                 } else {
 995                                         $contextNode = $iteratorNode[$index];
 996                                         $index++;
 997                                 }
 998                         } elseif ( $iteratorNode instanceof DOMNodeList ) {
 999                                 if ( $index >= $iteratorNode->length ) {
1000                                         // All done with this iterator
1001                                         $iteratorStack[$level] = false;
1002                                         $contextNode = false;
1003                                 } else {
1004                                         $contextNode = $iteratorNode->item( $index );
1005                                         $index++;
1006                                 }
1007                         } else {
1008                                 // Copy to $contextNode and then delete from iterator stack,
1009                                 // because this is not an iterator but we do have to execute it once
1010                                 $contextNode = $iteratorStack[$level];
1011                                 $iteratorStack[$level] = false;
1012                         }
1013
1014                         if ( $contextNode instanceof PPNode_DOM ) {
1015                                 $contextNode = $contextNode->node;
1016                         }
1017
1018                         $newIterator = false;
1019
1020                         if ( $contextNode === false ) {
1021                                 // nothing to do
1022                         } elseif ( is_string( $contextNode ) ) {
1023                                 $out .= $contextNode;
1024                         } elseif ( is_array( $contextNode ) || $contextNode instanceof DOMNodeList ) {
1025                                 $newIterator = $contextNode;
1026                         } elseif ( $contextNode instanceof DOMNode ) {
1027                                 if ( $contextNode->nodeType == XML_TEXT_NODE ) {
1028                                         $out .= $contextNode->nodeValue;
1029                                 } elseif ( $contextNode->nodeName == 'template' ) {
1030                                         # Double-brace expansion
1031                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1032                                         $titles = $xpath->query( 'title', $contextNode );
1033                                         $title = $titles->item( 0 );
1034                                         $parts = $xpath->query( 'part', $contextNode );
1035                                         if ( $flags & PPFrame::NO_TEMPLATES ) {
1036                                                 $newIterator = $this->virtualBracketedImplode( '{{', '|', '}}', $title, $parts );
1037                                         } else {
1038                                                 $lineStart = $contextNode->getAttribute( 'lineStart' );
1039                                                 $params = array(
1040                                                         'title' => new PPNode_DOM( $title ),
1041                                                         'parts' => new PPNode_DOM( $parts ),
1042                                                         'lineStart' => $lineStart,
1043                                                         'interwiki' => $this->title->getInterwiki( ) );
1044                                                 $ret = $this->parser->braceSubstitution( $params, $this );
1045                                                 if ( isset( $ret['object'] ) ) {
1046                                                         $newIterator = $ret['object'];
1047                                                 } else {
1048                                                         $out .= $ret['text'];
1049                                                 }
1050                                         }
1051                                 } elseif ( $contextNode->nodeName == 'tplarg' ) {
1052                                         # Triple-brace expansion
1053                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1054                                         $titles = $xpath->query( 'title', $contextNode );
1055                                         $title = $titles->item( 0 );
1056                                         $parts = $xpath->query( 'part', $contextNode );
1057                                         if ( $flags & PPFrame::NO_ARGS ) {
1058                                                 $newIterator = $this->virtualBracketedImplode( '{{{', '|', '}}}', $title, $parts );
1059                                         } else {
1060                                                 $params = array(
1061                                                         'title' => new PPNode_DOM( $title ),
1062                                                         'parts' => new PPNode_DOM( $parts ) );
1063                                                 $ret = $this->parser->argSubstitution( $params, $this );
1064                                                 if ( isset( $ret['object'] ) ) {
1065                                                         $newIterator = $ret['object'];
1066                                                 } else {
1067                                                         $out .= $ret['text'];
1068                                                 }
1069                                         }
1070                                 } elseif ( $contextNode->nodeName == 'comment' ) {
1071                                         # HTML-style comment
1072                                         # Remove it in HTML, pre+remove and STRIP_COMMENTS modes
1073                                         if ( $this->parser->ot['html']
1074                                                 || ( $this->parser->ot['pre'] && $this->parser->mOptions->getRemoveComments() )
1075                                                 || ( $flags & PPFrame::STRIP_COMMENTS ) )
1076                                         {
1077                                                 $out .= '';
1078                                         }
1079                                         # Add a strip marker in PST mode so that pstPass2() can run some old-fashioned regexes on the result
1080                                         # Not in RECOVER_COMMENTS mode (extractSections) though
1081                                         elseif ( $this->parser->ot['wiki'] && ! ( $flags & PPFrame::RECOVER_COMMENTS ) ) {
1082                                                 $out .= $this->parser->insertStripItem( $contextNode->textContent );
1083                                         }
1084                                         # Recover the literal comment in RECOVER_COMMENTS and pre+no-remove
1085                                         else {
1086                                                 $out .= $contextNode->textContent;
1087                                         }
1088                                 } elseif ( $contextNode->nodeName == 'ignore' ) {
1089                                         # Output suppression used by <includeonly> etc.
1090                                         # OT_WIKI will only respect <ignore> in substed templates.
1091                                         # The other output types respect it unless NO_IGNORE is set.
1092                                         # extractSections() sets NO_IGNORE and so never respects it.
1093                                         if ( ( !isset( $this->parent ) && $this->parser->ot['wiki'] ) || ( $flags & PPFrame::NO_IGNORE ) ) {
1094                                                 $out .= $contextNode->textContent;
1095                                         } else {
1096                                                 $out .= '';
1097                                         }
1098                                 } elseif ( $contextNode->nodeName == 'ext' ) {
1099                                         # Extension tag
1100                                         $xpath = new DOMXPath( $contextNode->ownerDocument );
1101                                         $names = $xpath->query( 'name', $contextNode );
1102                                         $attrs = $xpath->query( 'attr', $contextNode );
1103                                         $inners = $xpath->query( 'inner', $contextNode );
1104                                         $closes = $xpath->query( 'close', $contextNode );
1105                                         $params = array(
1106                                                 'name' => new PPNode_DOM( $names->item( 0 ) ),
1107                                                 'attr' => $attrs->length > 0 ? new PPNode_DOM( $attrs->item( 0 ) ) : null,
1108                                                 'inner' => $inners->length > 0 ? new PPNode_DOM( $inners->item( 0 ) ) : null,
1109                                                 'close' => $closes->length > 0 ? new PPNode_DOM( $closes->item( 0 ) ) : null,
1110                                         );
1111                                         $out .= $this->parser->extensionSubstitution( $params, $this );
1112                                 } elseif ( $contextNode->nodeName == 'h' ) {
1113                                         # Heading
1114                                         $s = $this->expand( $contextNode->childNodes, $flags );
1115
1116                                         # Insert a heading marker only for <h> children of <root>
1117                                         # This is to stop extractSections from going over multiple tree levels
1118                                         if ( $contextNode->parentNode->nodeName == 'root'
1119                                           && $this->parser->ot['html'] )
1120                                         {
1121                                                 # Insert heading index marker
1122                                                 $headingIndex = $contextNode->getAttribute( 'i' );
1123                                                 $titleText = $this->title->getPrefixedDBkey();
1124                                                 $this->parser->mHeadings[] = array( $titleText, $headingIndex );
1125                                                 $serial = count( $this->parser->mHeadings ) - 1;
1126                                                 $marker = "{$this->parser->mUniqPrefix}-h-$serial-" . Parser::MARKER_SUFFIX;
1127                                                 $count = $contextNode->getAttribute( 'level' );
1128                                                 $s = substr( $s, 0, $count ) . $marker . substr( $s, $count );
1129                                                 $this->parser->mStripState->addGeneral( $marker, '' );
1130                                         }
1131                                         $out .= $s;
1132                                 } else {
1133                                         # Generic recursive expansion
1134                                         $newIterator = $contextNode->childNodes;
1135                                 }
1136                         } else {
1137                                 wfProfileOut( __METHOD__ );
1138                                 throw new MWException( __METHOD__.': Invalid parameter type' );
1139                         }
1140
1141                         if ( $newIterator !== false ) {
1142                                 if ( $newIterator instanceof PPNode_DOM ) {
1143                                         $newIterator = $newIterator->node;
1144                                 }
1145                                 $outStack[] = '';
1146                                 $iteratorStack[] = $newIterator;
1147                                 $indexStack[] = 0;
1148                         } elseif ( $iteratorStack[$level] === false ) {
1149                                 // Return accumulated value to parent
1150                                 // With tail recursion
1151                                 while ( $iteratorStack[$level] === false && $level > 0 ) {
1152                                         $outStack[$level - 1] .= $out;
1153                                         array_pop( $outStack );
1154                                         array_pop( $iteratorStack );
1155                                         array_pop( $indexStack );
1156                                         $level--;
1157                                 }
1158                         }
1159                 }
1160                 --$expansionDepth;
1161                 wfProfileOut( __METHOD__ );
1162                 return $outStack[0];
1163         }
1164
1165         /**
1166          * @param $sep
1167          * @param $flags
1168          * @return string
1169          */
1170         function implodeWithFlags( $sep, $flags /*, ... */ ) {
1171                 $args = array_slice( func_get_args(), 2 );
1172
1173                 $first = true;
1174                 $s = '';
1175                 foreach ( $args as $root ) {
1176                         if ( $root instanceof PPNode_DOM ) $root = $root->node;
1177                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1178                                 $root = array( $root );
1179                         }
1180                         foreach ( $root as $node ) {
1181                                 if ( $first ) {
1182                                         $first = false;
1183                                 } else {
1184                                         $s .= $sep;
1185                                 }
1186                                 $s .= $this->expand( $node, $flags );
1187                         }
1188                 }
1189                 return $s;
1190         }
1191
1192         /**
1193          * Implode with no flags specified
1194          * This previously called implodeWithFlags but has now been inlined to reduce stack depth
1195          *
1196          * @return string
1197          */
1198         function implode( $sep /*, ... */ ) {
1199                 $args = array_slice( func_get_args(), 1 );
1200
1201                 $first = true;
1202                 $s = '';
1203                 foreach ( $args as $root ) {
1204                         if ( $root instanceof PPNode_DOM ) {
1205                                 $root = $root->node;
1206                         }
1207                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1208                                 $root = array( $root );
1209                         }
1210                         foreach ( $root as $node ) {
1211                                 if ( $first ) {
1212                                         $first = false;
1213                                 } else {
1214                                         $s .= $sep;
1215                                 }
1216                                 $s .= $this->expand( $node );
1217                         }
1218                 }
1219                 return $s;
1220         }
1221
1222         /**
1223          * Makes an object that, when expand()ed, will be the same as one obtained
1224          * with implode()
1225          *
1226          * @return array
1227          */
1228         function virtualImplode( $sep /*, ... */ ) {
1229                 $args = array_slice( func_get_args(), 1 );
1230                 $out = array();
1231                 $first = true;
1232
1233                 foreach ( $args as $root ) {
1234                         if ( $root instanceof PPNode_DOM ) {
1235                                 $root = $root->node;
1236                         }
1237                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1238                                 $root = array( $root );
1239                         }
1240                         foreach ( $root as $node ) {
1241                                 if ( $first ) {
1242                                         $first = false;
1243                                 } else {
1244                                         $out[] = $sep;
1245                                 }
1246                                 $out[] = $node;
1247                         }
1248                 }
1249                 return $out;
1250         }
1251
1252         /**
1253          * Virtual implode with brackets
1254          */
1255         function virtualBracketedImplode( $start, $sep, $end /*, ... */ ) {
1256                 $args = array_slice( func_get_args(), 3 );
1257                 $out = array( $start );
1258                 $first = true;
1259
1260                 foreach ( $args as $root ) {
1261                         if ( $root instanceof PPNode_DOM ) {
1262                                 $root = $root->node;
1263                         }
1264                         if ( !is_array( $root ) && !( $root instanceof DOMNodeList ) ) {
1265                                 $root = array( $root );
1266                         }
1267                         foreach ( $root as $node ) {
1268                                 if ( $first ) {
1269                                         $first = false;
1270                                 } else {
1271                                         $out[] = $sep;
1272                                 }
1273                                 $out[] = $node;
1274                         }
1275                 }
1276                 $out[] = $end;
1277                 return $out;
1278         }
1279
1280         function __toString() {
1281                 return 'frame{}';
1282         }
1283
1284         function getPDBK( $level = false ) {
1285                 if ( $level === false ) {
1286                         return $this->title->getPrefixedDBkey();
1287                 } else {
1288                         return isset( $this->titleCache[$level] ) ? $this->titleCache[$level] : false;
1289                 }
1290         }
1291
1292         /**
1293          * @return array
1294          */
1295         function getArguments() {
1296                 return array();
1297         }
1298
1299         /**
1300          * @return array
1301          */
1302         function getNumberedArguments() {
1303                 return array();
1304         }
1305
1306         /**
1307          * @return array
1308          */
1309         function getNamedArguments() {
1310                 return array();
1311         }
1312
1313         /**
1314          * Returns true if there are no arguments in this frame
1315          *
1316          * @return bool
1317          */
1318         function isEmpty() {
1319                 return true;
1320         }
1321
1322         function getArgument( $name ) {
1323                 return false;
1324         }
1325
1326         /**
1327          * Returns true if the infinite loop check is OK, false if a loop is detected
1328          *
1329          * @return bool
1330          */
1331         function loopCheck( $title ) {
1332                 return !isset( $this->loopCheckHash[$title->getPrefixedDBkey()] );
1333         }
1334
1335         /**
1336          * Return true if the frame is a template frame
1337          *
1338          * @return bool
1339          */
1340         function isTemplate() {
1341                 return false;
1342         }
1343 }
1344
1345 /**
1346  * Expansion frame with template arguments
1347  * @ingroup Parser
1348  */
1349 class PPTemplateFrame_DOM extends PPFrame_DOM {
1350         var $numberedArgs, $namedArgs;
1351
1352         /**
1353          * @var PPFrame_DOM
1354          */
1355         var $parent;
1356         var $numberedExpansionCache, $namedExpansionCache;
1357
1358         /**
1359          * @param $preprocessor
1360          * @param $parent PPFrame_DOM
1361          * @param $numberedArgs array
1362          * @param $namedArgs array
1363          * @param $title Title
1364          */
1365         function __construct( $preprocessor, $parent = false, $numberedArgs = array(), $namedArgs = array(), $title = false ) {
1366                 parent::__construct( $preprocessor );
1367
1368                 $this->parent = $parent;
1369                 $this->numberedArgs = $numberedArgs;
1370                 $this->namedArgs = $namedArgs;
1371                 $this->title = $title;
1372                 $pdbk = $title ? $title->getPrefixedDBkey() : false;
1373                 $this->titleCache = $parent->titleCache;
1374                 $this->titleCache[] = $pdbk;
1375                 $this->loopCheckHash = /*clone*/ $parent->loopCheckHash;
1376                 if ( $pdbk !== false ) {
1377                         $this->loopCheckHash[$pdbk] = true;
1378                 }
1379                 $this->depth = $parent->depth + 1;
1380                 $this->numberedExpansionCache = $this->namedExpansionCache = array();
1381         }
1382
1383         function __toString() {
1384                 $s = 'tplframe{';
1385                 $first = true;
1386                 $args = $this->numberedArgs + $this->namedArgs;
1387                 foreach ( $args as $name => $value ) {
1388                         if ( $first ) {
1389                                 $first = false;
1390                         } else {
1391                                 $s .= ', ';
1392                         }
1393                         $s .= "\"$name\":\"" .
1394                                 str_replace( '"', '\\"', $value->ownerDocument->saveXML( $value ) ) . '"';
1395                 }
1396                 $s .= '}';
1397                 return $s;
1398         }
1399
1400         /**
1401          * Returns true if there are no arguments in this frame
1402          *
1403          * @return bool
1404          */
1405         function isEmpty() {
1406                 return !count( $this->numberedArgs ) && !count( $this->namedArgs );
1407         }
1408
1409         function getArguments() {
1410                 $arguments = array();
1411                 foreach ( array_merge(
1412                                 array_keys($this->numberedArgs),
1413                                 array_keys($this->namedArgs)) as $key ) {
1414                         $arguments[$key] = $this->getArgument($key);
1415                 }
1416                 return $arguments;
1417         }
1418
1419         function getNumberedArguments() {
1420                 $arguments = array();
1421                 foreach ( array_keys($this->numberedArgs) as $key ) {
1422                         $arguments[$key] = $this->getArgument($key);
1423                 }
1424                 return $arguments;
1425         }
1426
1427         function getNamedArguments() {
1428                 $arguments = array();
1429                 foreach ( array_keys($this->namedArgs) as $key ) {
1430                         $arguments[$key] = $this->getArgument($key);
1431                 }
1432                 return $arguments;
1433         }
1434
1435         function getNumberedArgument( $index ) {
1436                 if ( !isset( $this->numberedArgs[$index] ) ) {
1437                         return false;
1438                 }
1439                 if ( !isset( $this->numberedExpansionCache[$index] ) ) {
1440                         # No trimming for unnamed arguments
1441                         $this->numberedExpansionCache[$index] = $this->parent->expand( $this->numberedArgs[$index], PPFrame::STRIP_COMMENTS );
1442                 }
1443                 return $this->numberedExpansionCache[$index];
1444         }
1445
1446         function getNamedArgument( $name ) {
1447                 if ( !isset( $this->namedArgs[$name] ) ) {
1448                         return false;
1449                 }
1450                 if ( !isset( $this->namedExpansionCache[$name] ) ) {
1451                         # Trim named arguments post-expand, for backwards compatibility
1452                         $this->namedExpansionCache[$name] = trim(
1453                                 $this->parent->expand( $this->namedArgs[$name], PPFrame::STRIP_COMMENTS ) );
1454                 }
1455                 return $this->namedExpansionCache[$name];
1456         }
1457
1458         function getArgument( $name ) {
1459                 $text = $this->getNumberedArgument( $name );
1460                 if ( $text === false ) {
1461                         $text = $this->getNamedArgument( $name );
1462                 }
1463                 return $text;
1464         }
1465
1466         /**
1467          * Return true if the frame is a template frame
1468          *
1469          * @return bool
1470          */
1471         function isTemplate() {
1472                 return true;
1473         }
1474 }
1475
1476 /**
1477  * Expansion frame with custom arguments
1478  * @ingroup Parser
1479  */
1480 class PPCustomFrame_DOM extends PPFrame_DOM {
1481         var $args;
1482
1483         function __construct( $preprocessor, $args ) {
1484                 parent::__construct( $preprocessor );
1485                 $this->args = $args;
1486         }
1487
1488         function __toString() {
1489                 $s = 'cstmframe{';
1490                 $first = true;
1491                 foreach ( $this->args as $name => $value ) {
1492                         if ( $first ) {
1493                                 $first = false;
1494                         } else {
1495                                 $s .= ', ';
1496                         }
1497                         $s .= "\"$name\":\"" .
1498                                 str_replace( '"', '\\"', $value->__toString() ) . '"';
1499                 }
1500                 $s .= '}';
1501                 return $s;
1502         }
1503
1504         /**
1505          * @return bool
1506          */
1507         function isEmpty() {
1508                 return !count( $this->args );
1509         }
1510
1511         function getArgument( $index ) {
1512                 if ( !isset( $this->args[$index] ) ) {
1513                         return false;
1514                 }
1515                 return $this->args[$index];
1516         }
1517 }
1518
1519 /**
1520  * @ingroup Parser
1521  */
1522 class PPNode_DOM implements PPNode {
1523
1524         /**
1525          * @var DOMElement
1526          */
1527         var $node;
1528         var $xpath;
1529
1530         function __construct( $node, $xpath = false ) {
1531                 $this->node = $node;
1532         }
1533
1534         /**
1535          * @return DOMXPath
1536          */
1537         function getXPath() {
1538                 if ( $this->xpath === null ) {
1539                         $this->xpath = new DOMXPath( $this->node->ownerDocument );
1540                 }
1541                 return $this->xpath;
1542         }
1543
1544         function __toString() {
1545                 if ( $this->node instanceof DOMNodeList ) {
1546                         $s = '';
1547                         foreach ( $this->node as $node ) {
1548                                 $s .= $node->ownerDocument->saveXML( $node );
1549                         }
1550                 } else {
1551                         $s = $this->node->ownerDocument->saveXML( $this->node );
1552                 }
1553                 return $s;
1554         }
1555
1556         /**
1557          * @return bool|PPNode_DOM
1558          */
1559         function getChildren() {
1560                 return $this->node->childNodes ? new self( $this->node->childNodes ) : false;
1561         }
1562
1563         /**
1564          * @return bool|PPNode_DOM
1565          */
1566         function getFirstChild() {
1567                 return $this->node->firstChild ? new self( $this->node->firstChild ) : false;
1568         }
1569
1570         /**
1571          * @return bool|PPNode_DOM
1572          */
1573         function getNextSibling() {
1574                 return $this->node->nextSibling ? new self( $this->node->nextSibling ) : false;
1575         }
1576
1577         /**
1578          * @param $type
1579          *
1580          * @return bool|PPNode_DOM
1581          */
1582         function getChildrenOfType( $type ) {
1583                 return new self( $this->getXPath()->query( $type, $this->node ) );
1584         }
1585
1586         /**
1587          * @return int
1588          */
1589         function getLength() {
1590                 if ( $this->node instanceof DOMNodeList ) {
1591                         return $this->node->length;
1592                 } else {
1593                         return false;
1594                 }
1595         }
1596
1597         /**
1598          * @param $i
1599          * @return bool|PPNode_DOM
1600          */
1601         function item( $i ) {
1602                 $item = $this->node->item( $i );
1603                 return $item ? new self( $item ) : false;
1604         }
1605
1606         /**
1607          * @return string
1608          */
1609         function getName() {
1610                 if ( $this->node instanceof DOMNodeList ) {
1611                         return '#nodelist';
1612                 } else {
1613                         return $this->node->nodeName;
1614                 }
1615         }
1616
1617         /**
1618          * Split a <part> node into an associative array containing:
1619          *    name          PPNode name
1620          *    index         String index
1621          *    value         PPNode value
1622          *
1623          * @return array
1624          */
1625         function splitArg() {
1626                 $xpath = $this->getXPath();
1627                 $names = $xpath->query( 'name', $this->node );
1628                 $values = $xpath->query( 'value', $this->node );
1629                 if ( !$names->length || !$values->length ) {
1630                         throw new MWException( 'Invalid brace node passed to ' . __METHOD__ );
1631                 }
1632                 $name = $names->item( 0 );
1633                 $index = $name->getAttribute( 'index' );
1634                 return array(
1635                         'name' => new self( $name ),
1636                         'index' => $index,
1637                         'value' => new self( $values->item( 0 ) ) );
1638         }
1639
1640         /**
1641          * Split an <ext> node into an associative array containing name, attr, inner and close
1642          * All values in the resulting array are PPNodes. Inner and close are optional.
1643          *
1644          * @return array
1645          */
1646         function splitExt() {
1647                 $xpath = $this->getXPath();
1648                 $names = $xpath->query( 'name', $this->node );
1649                 $attrs = $xpath->query( 'attr', $this->node );
1650                 $inners = $xpath->query( 'inner', $this->node );
1651                 $closes = $xpath->query( 'close', $this->node );
1652                 if ( !$names->length || !$attrs->length ) {
1653                         throw new MWException( 'Invalid ext node passed to ' . __METHOD__ );
1654                 }
1655                 $parts = array(
1656                         'name' => new self( $names->item( 0 ) ),
1657                         'attr' => new self( $attrs->item( 0 ) ) );
1658                 if ( $inners->length ) {
1659                         $parts['inner'] = new self( $inners->item( 0 ) );
1660                 }
1661                 if ( $closes->length ) {
1662                         $parts['close'] = new self( $closes->item( 0 ) );
1663                 }
1664                 return $parts;
1665         }
1666
1667         /**
1668          * Split a <h> node
1669          */
1670         function splitHeading() {
1671                 if ( $this->getName() !== 'h' ) {
1672                         throw new MWException( 'Invalid h node passed to ' . __METHOD__ );
1673                 }
1674                 return array(
1675                         'i' => $this->node->getAttribute( 'i' ),
1676                         'level' => $this->node->getAttribute( 'level' ),
1677                         'contents' => $this->getChildren()
1678                 );
1679         }
1680 }