egroupware/phpgwapi/inc/htmlpurifier/library/HTMLPurifier/Lexer/PEARSax3.php
Ralf Becker 8f797be836 Added HTMLPurifier (http://htmlpurifier.org/) Version 3.3.0
- can be used via html class like: 

        $clean_html = html::purify($html);

- using it now in eTemplate to remove malicious code from html:
  a) when displaying "formatted text"
  b) when "formatted text" get's input by the user
2009-05-19 17:32:06 +00:00

107 lines
3.4 KiB
PHP
Executable File

<?php
/**
* Proof-of-concept lexer that uses the PEAR package XML_HTMLSax3 to parse HTML.
*
* PEAR, not suprisingly, also has a SAX parser for HTML. I don't know
* very much about implementation, but it's fairly well written. However, that
* abstraction comes at a price: performance. You need to have it installed,
* and if the API changes, it might break our adapter. Not sure whether or not
* it's UTF-8 aware, but it has some entity parsing trouble (in all areas,
* text and attributes).
*
* Quite personally, I don't recommend using the PEAR class, and the defaults
* don't use it. The unit tests do perform the tests on the SAX parser too, but
* whatever it does for poorly formed HTML is up to it.
*
* @todo Generalize so that XML_HTMLSax is also supported.
*
* @warning Entity-resolution inside attributes is broken.
*/
class HTMLPurifier_Lexer_PEARSax3 extends HTMLPurifier_Lexer
{
/**
* Internal accumulator array for SAX parsers.
*/
protected $tokens = array();
public function tokenizeHTML($string, $config, $context) {
$this->tokens = array();
$string = $this->normalize($string, $config, $context);
$parser = new XML_HTMLSax3();
$parser->set_object($this);
$parser->set_element_handler('openHandler','closeHandler');
$parser->set_data_handler('dataHandler');
$parser->set_escape_handler('escapeHandler');
// doesn't seem to work correctly for attributes
$parser->set_option('XML_OPTION_ENTITIES_PARSED', 1);
$parser->parse($string);
return $this->tokens;
}
/**
* Open tag event handler, interface is defined by PEAR package.
*/
public function openHandler(&$parser, $name, $attrs, $closed) {
// entities are not resolved in attrs
foreach ($attrs as $key => $attr) {
$attrs[$key] = $this->parseData($attr);
}
if ($closed) {
$this->tokens[] = new HTMLPurifier_Token_Empty($name, $attrs);
} else {
$this->tokens[] = new HTMLPurifier_Token_Start($name, $attrs);
}
return true;
}
/**
* Close tag event handler, interface is defined by PEAR package.
*/
public function closeHandler(&$parser, $name) {
// HTMLSax3 seems to always send empty tags an extra close tag
// check and ignore if you see it:
// [TESTME] to make sure it doesn't overreach
if ($this->tokens[count($this->tokens)-1] instanceof HTMLPurifier_Token_Empty) {
return true;
}
$this->tokens[] = new HTMLPurifier_Token_End($name);
return true;
}
/**
* Data event handler, interface is defined by PEAR package.
*/
public function dataHandler(&$parser, $data) {
$this->tokens[] = new HTMLPurifier_Token_Text($data);
return true;
}
/**
* Escaped text handler, interface is defined by PEAR package.
*/
public function escapeHandler(&$parser, $data) {
if (strpos($data, '--') === 0) {
$this->tokens[] = new HTMLPurifier_Token_Comment($data);
}
// CDATA is handled elsewhere, but if it was handled here:
//if (strpos($data, '[CDATA[') === 0) {
// $this->tokens[] = new HTMLPurifier_Token_Text(
// substr($data, 7, strlen($data) - 9) );
//}
return true;
}
}
// vim: et sw=4 sts=4