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