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- <?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
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