<?php/** * Parser that uses PHP 5's DOM extension (part of the core). * * In PHP 5, the DOM XML extension was revamped into DOM and added to the core. * It gives us a forgiving HTML parser, which we use to transform the HTML * into a DOM, and then into the tokens. It is blazingly fast (for large * documents, it performs twenty times faster than * HTMLPurifier_Lexer_DirectLex,and is the default choice for PHP 5. * * @note Any empty elements will have empty tokens associated with them, even if * this is prohibited by the spec. This is cannot be fixed until the spec * comes into play. * * @note PHP's DOM extension does not actually parse any entities, we use * our own function to do that. * * @warning DOM tends to drop whitespace, which may wreak havoc on indenting. * If this is a huge problem, due to the fact that HTML is hand * edited and you are unable to get a parser cache that caches the * the output of HTML Purifier while keeping the original HTML lying * around, you may want to run Tidy on the resulting output or use * HTMLPurifier_DirectLex */class HTMLPurifier_Lexer_DOMLex extends HTMLPurifier_Lexer{ /** * @type HTMLPurifier_TokenFactory */ private $factory; public function __construct() { // setup the factory parent::__construct(); $this->factory = new HTMLPurifier_TokenFactory(); } /** * @param string $html * @param HTMLPurifier_Config $config * @param HTMLPurifier_Context $context * @return HTMLPurifier_Token[] */ public function tokenizeHTML($html, $config, $context) { $html = $this->normalize($html, $config, $context); // attempt to armor stray angled brackets that cannot possibly // form tags and thus are probably being used as emoticons if ($config->get('Core.AggressivelyFixLt')) { $char = '[^a-z!\/]'; $comment = "/<!--(.*?)(-->|\z)/is"; $html = preg_replace_callback($comment, array($this, 'callbackArmorCommentEntities'), $html); do { $old = $html; $html = preg_replace("/<($char)/i", '<\\1', $html); } while ($html !== $old); $html = preg_replace_callback($comment, array($this, 'callbackUndoCommentSubst'), $html); // fix comments } // preprocess html, essential for UTF-8 $html = $this->wrapHTML($html, $config, $context); $doc = new DOMDocument(); $doc->encoding = 'UTF-8'; // theoretically, the above has this covered $options = 0; if ($config->get('Core.AllowParseManyTags') && defined('LIBXML_PARSEHUGE')) { $options |= LIBXML_PARSEHUGE; } set_error_handler(array($this, 'muteErrorHandler')); // loadHTML() fails on PHP 5.3 when second parameter is given if ($options) { $doc->loadHTML($html, $options); } else { $doc->loadHTML($html); } restore_error_handler(); $body = $doc->getElementsByTagName('html')->item(0)-> // <html> getElementsByTagName('body')->item(0); // <body> $div = $body->getElementsByTagName('div')->item(0); // <div> $tokens = array(); $this->tokenizeDOM($div, $tokens, $config); // If the div has a sibling, that means we tripped across // a premature </div> tag. So remove the div we parsed, // and then tokenize the rest of body. We can't tokenize // the sibling directly as we'll lose the tags in that case. if ($div->nextSibling) { $body->removeChild($div); $this->tokenizeDOM($body, $tokens, $config); } return $tokens; } /** * Iterative function that tokenizes a node, putting it into an accumulator. * To iterate is human, to recurse divine - L. Peter Deutsch * @param DOMNode $node DOMNode to be tokenized. * @param HTMLPurifier_Token[] $tokens Array-list of already tokenized tokens. * @return HTMLPurifier_Token of node appended to previously passed tokens. */ protected function tokenizeDOM($node, &$tokens, $config) { $level = 0; $nodes = array($level => new HTMLPurifier_Queue(array($node))); $closingNodes = array(); do { while (!$nodes[$level]->isEmpty()) { $node = $nodes[$level]->shift(); // FIFO $collect = $level > 0 ? true : false; $needEndingTag = $this->createStartNode($node, $tokens, $collect, $config); if ($needEndingTag) { $closingNodes[$level][] = $node; } if ($node->childNodes && $node->childNodes->length) { $level++; $nodes[$level] = new HTMLPurifier_Queue(); foreach ($node->childNodes as $childNode) { $nodes[$level]->push($childNode); } } } $level--; if ($level && isset($closingNodes[$level])) { while ($node = array_pop($closingNodes[$level])) { $this->createEndNode($node, $tokens); } } } while ($level > 0); } /** * Portably retrieve the tag name of a node; deals with older versions * of libxml like 2.7.6 * @param DOMNode $node */ protected function getTagName($node) { if (isset($node->tagName)) { return $node->tagName; } else if (isset($node->nodeName)) { return $node->nodeName; } else if (isset($node->localName)) { return $node->localName; } return null; } /** * Portably retrieve the data of a node; deals with older versions * of libxml like 2.7.6 * @param DOMNode $node */ protected function getData($node) { if (isset($node->data)) { return $node->data; } else if (isset($node->nodeValue)) { return $node->nodeValue; } else if (isset($node->textContent)) { return $node->textContent; } return null; } /** * @param DOMNode $node DOMNode to be tokenized. * @param HTMLPurifier_Token[] $tokens Array-list of already tokenized tokens. * @param bool $collect Says whether or start and close are collected, set to * false at first recursion because it's the implicit DIV * tag you're dealing with. * @return bool if the token needs an endtoken * @todo data and tagName properties don't seem to exist in DOMNode? */ protected function createStartNode($node, &$tokens, $collect, $config) { // intercept non element nodes. WE MUST catch all of them, // but we're not getting the character reference nodes because // those should have been preprocessed if ($node->nodeType === XML_TEXT_NODE) { $data = $this->getData($node); // Handle variable data property if ($data !== null) { $tokens[] = $this->factory->createText($data); } return false; } elseif ($node->nodeType === XML_CDATA_SECTION_NODE) { // undo libxml's special treatment of <script> and <style> tags $last = end($tokens); $data = $node->data; // (note $node->tagname is already normalized) if ($last instanceof HTMLPurifier_Token_Start && ($last->name == 'script' || $last->name == 'style')) { $new_data = trim($data); if (substr($new_data, 0, 4) === '<!--') { $data = substr($new_data, 4); if (substr($data, -3) === '-->') { $data = substr($data, 0, -3); } else { // Highly suspicious! Not sure what to do... } } } $tokens[] = $this->factory->createText($this->parseText($data, $config)); return false; } elseif ($node->nodeType === XML_COMMENT_NODE) { // this is code is only invoked for comments in script/style in versions // of libxml pre-2.6.28 (regular comments, of course, are still // handled regularly) $tokens[] = $this->factory->createComment($node->data); return false; } elseif ($node->nodeType !== XML_ELEMENT_NODE) { // not-well tested: there may be other nodes we have to grab return false; } $attr = $node->hasAttributes() ? $this->transformAttrToAssoc($node->attributes) : array(); $tag_name = $this->getTagName($node); // Handle variable tagName property if (empty($tag_name)) { return (bool) $node->childNodes->length; } // We still have to make sure that the element actually IS empty if (!$node->childNodes->length) { if ($collect) { $tokens[] = $this->factory->createEmpty($tag_name, $attr); } return false; } else { if ($collect) { $tokens[] = $this->factory->createStart($tag_name, $attr); } return true; } } /** * @param DOMNode $node * @param HTMLPurifier_Token[] $tokens */ protected function createEndNode($node, &$tokens) { $tag_name = $this->getTagName($node); // Handle variable tagName property $tokens[] = $this->factory->createEnd($tag_name); } /** * Converts a DOMNamedNodeMap of DOMAttr objects into an assoc array. * * @param DOMNamedNodeMap $node_map DOMNamedNodeMap of DOMAttr objects. * @return array Associative array of attributes. */ protected function transformAttrToAssoc($node_map) { // NamedNodeMap is documented very well, so we're using undocumented // features, namely, the fact that it implements Iterator and // has a ->length attribute if ($node_map->length === 0) { return array(); } $array = array(); foreach ($node_map as $attr) { $array[$attr->name] = $attr->value; } return $array; } /** * An error handler that mutes all errors * @param int $errno * @param string $errstr */ public function muteErrorHandler($errno, $errstr) { } /** * Callback function for undoing escaping of stray angled brackets * in comments * @param array $matches * @return string */ public function callbackUndoCommentSubst($matches) { return '<!--' . strtr($matches[1], array('&' => '&', '<' => '<')) . $matches[2]; } /** * Callback function that entity-izes ampersands in comments so that * callbackUndoCommentSubst doesn't clobber them * @param array $matches * @return string */ public function callbackArmorCommentEntities($matches) { return '<!--' . str_replace('&', '&', $matches[1]) . $matches[2]; } /** * Wraps an HTML fragment in the necessary HTML * @param string $html * @param HTMLPurifier_Config $config * @param HTMLPurifier_Context $context * @return string */ protected function wrapHTML($html, $config, $context, $use_div = true) { $def = $config->getDefinition('HTML'); $ret = ''; if (!empty($def->doctype->dtdPublic) || !empty($def->doctype->dtdSystem)) { $ret .= '<!DOCTYPE html '; if (!empty($def->doctype->dtdPublic)) { $ret .= 'PUBLIC "' . $def->doctype->dtdPublic . '" '; } if (!empty($def->doctype->dtdSystem)) { $ret .= '"' . $def->doctype->dtdSystem . '" '; } $ret .= '>'; } $ret .= '<html><head>'; $ret .= '<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />'; // No protection if $html contains a stray </div>! $ret .= '</head><body>'; if ($use_div) $ret .= '<div>'; $ret .= $html; if ($use_div) $ret .= '</div>'; $ret .= '</body></html>'; return $ret; }}// vim: et sw=4 sts=4