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