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