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htmlpurifier/library/HTMLPurifier/Lexer/DOMLex.php

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<?php
require_once 'HTMLPurifier/Lexer.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.
*
* @notice
* 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.
*
* @todo Determine DOM's entity parsing behavior, point to local entity files
* if necessary.
* @todo Make div access less fragile, and refrain from preprocessing when
* HTML tag and friends are already present.
*/
class HTMLPurifier_Lexer_DOMLex extends HTMLPurifier_Lexer
{
public function tokenizeHTML($string) {
$doc = new DOMDocument();
// preprocess string
$string = '<html><body><div>'.$string.'</div></body></html>';
// replace and escape the CDATA sections, since parsing under HTML
// mode won't get 'em.
$string = $this->escapeCDATA($string);
@$doc->loadHTML($string); // mute all errors, handle it transparently
return $this->tokenizeDOM(
$doc->childNodes->item(1)-> // html
childNodes->item(0)-> // body
childNodes->item(0) // div
);
}
/**
* Recursive function that tokenizes a node, putting it into an accumulator.
*
* @param $node DOMNode to be tokenized.
* @param $tokens Array-list of already tokenized tokens.
* @param $collect Says whether or start and close are collected, set to
* false at first recursion because it's the implicit DIV
* tag you're dealing with.
* @returns Tokens of node appended to previously passed tokens.
*/
protected function tokenizeDOM($node, $tokens = array(), $collect = false) {
// recursive goodness!
// intercept non element nodes
if ( !($node instanceof DOMElement) ) {
if ($node instanceof DOMComment) {
$tokens[] = new HTMLPurifier_Token_Comment($node->data);
} elseif ($node instanceof DOMText ||
$node instanceof DOMCharacterData) {
$tokens[] = new HTMLPurifier_Token_Text($node->data);
}
// quite possibly, the object wasn't handled, that's fine
return $tokens;
}
// We still have to make sure that the element actually IS empty
if (!$node->hasChildNodes()) {
if ($collect) {
$tokens[] = new HTMLPurifier_Token_Empty(
$node->tagName,
$this->transformAttrToAssoc($node->attributes)
);
}
} else {
if ($collect) { // don't wrap on first iteration
$tokens[] = new HTMLPurifier_Token_Start(
$tag_name = $node->tagName, // somehow, it get's dropped
$this->transformAttrToAssoc($node->attributes)
);
}
foreach ($node->childNodes as $node) {
// remember, it's an accumulator. Otherwise, we'd have
// to use array_merge
$tokens = $this->tokenizeDOM($node, $tokens, true);
}
if ($collect) {
$tokens[] = new HTMLPurifier_Token_End($tag_name);
}
}
return $tokens;
}
/**
* Converts a DOMNamedNodeMap of DOMAttr objects into an assoc array.
*
* @param $attribute_list DOMNamedNodeMap of DOMAttr objects.
* @returns Associative array of attributes.
*/
protected function transformAttrToAssoc($attribute_list) {
$attribute_array = array();
// undocumented behavior
foreach ($attribute_list as $key => $attr) {
$attribute_array[$key] = $attr->value;
}
return $attribute_array;
}
}
?>