<?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(); protected $last_token_was_empty; private $parent_handler; private $stack = array(); public function tokenizeHTML($string, $config, $context) { $this->tokens = array(); $this->last_token_was_empty = false; $string = $this->normalize($string, $config, $context); $this->parent_handler = set_error_handler(array($this, 'muteStrictErrorHandler')); $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); restore_error_handler(); 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); $this->last_token_was_empty = true; } else { $this->tokens[] = new HTMLPurifier_Token_Start($name, $attrs); } $this->stack[] = $name; return true; } /** * Close tag event handler, interface is defined by PEAR package. */ public function closeHandler(&$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->last_token_was_empty) { $this->last_token_was_empty = false; return true; } $this->tokens[] = new HTMLPurifier_Token_End($name); if (!empty($this->stack)) array_pop($this->stack); return true; } /** * Data event handler, interface is defined by PEAR package. */ public function dataHandler(&$parser, $data) { $this->last_token_was_empty = false; $this->tokens[] = new HTMLPurifier_Token_Text($data); return true; } /** * Escaped text handler, interface is defined by PEAR package. */ public function escapeHandler(&$parser, $data) { if (strpos($data, '--') === 0) { // remove trailing and leading double-dashes $data = substr($data, 2); if (strlen($data) >= 2 && substr($data, -2) == "--") { $data = substr($data, 0, -2); } if (isset($this->stack[sizeof($this->stack) - 1]) && $this->stack[sizeof($this->stack) - 1] == "style") { $this->tokens[] = new HTMLPurifier_Token_Text($data); } else { $this->tokens[] = new HTMLPurifier_Token_Comment($data); } $this->last_token_was_empty = false; } // CDATA is handled elsewhere, but if it was handled here: //if (strpos($data, '[CDATA[') === 0) { // $this->tokens[] = new HTMLPurifier_Token_Text( // substr($data, 7, strlen($data) - 9) ); //} return true; } /** * An error handler that mutes strict errors */ public function muteStrictErrorHandler($errno, $errstr, $errfile=null, $errline=null, $errcontext=null) { if ($errno == E_STRICT) return; return call_user_func($this->parent_handler, $errno, $errstr, $errfile, $errline, $errcontext); } } // vim: et sw=4 sts=4