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htmlpurifier/library/HTMLPurifier/Lexer/DirectLex.php
Edward Z. Yang 14f481bcf6 svn:eol-style = native
git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@97 48356398-32a2-884e-a903-53898d9a118a
2006-07-23 00:11:03 +00:00

354 lines
13 KiB
PHP

<?php
/*
TODO:
* Reread the XML spec and make sure I got everything right
* Add support for CDATA sections
* Have comments output with the leading and trailing --s
* Optimize and benchmark
* Check MF_Text behavior: shouldn't the info in there be raw (entities parsed?)
*/
require_once 'HTMLPurifier/Lexer.php';
class HTMLPurifier_Lexer_DirectLex extends HTMLPurifier_Lexer
{
// does this version of PHP support utf8 as entity function charset?
var $_entity_utf8;
function HTMLPurifier_Lexer() {
$this->_entity_utf8 = version_compare(PHP_VERSION, '5', '>=');
}
// this is QUITE a knotty problem
//
// The main trouble is that, even while assuming UTF-8 is what we're
// using, we've got to deal with HTML entities (like &mdash;)
// Not even sure if the PHP 5 decoding function does that. Plus,
// SimpleTest doesn't use UTF-8!
//
// However, we MUST parse everything possible, because once you get
// to the HTML generator, it will escape everything possible (although
// that may not be correct, and we should be using htmlspecialchars() ).
//
// Nevertheless, strictly XML speaking, we cannot assume any character
// entities are defined except the htmlspecialchars() ones, so leaving
// the entities inside HERE is not acceptable. (plus, htmlspecialchars
// might convert them anyway). So EVERYTHING must get parsed.
//
// We may need to roll our own character entity lookup table. It's only
// about 250, fortunantely, the decimal/hex ones map cleanly to UTF-8.
function parseData($string) {
// we may want to let the user do a different char encoding,
// although there is NO REASON why they shouldn't be able
// to convert it to UTF-8 before they pass it to us
// no support for less than PHP 4.3
if ($this->_entity_utf8) {
// PHP 5+, UTF-8 is nicely supported
return @html_entity_decode($string, ENT_QUOTES, 'UTF-8');
} else {
// PHP 4, do compat stuff
$string = html_entity_decode($string, ENT_QUOTES, 'ISO-8859-1');
// get the numeric UTF-8 stuff
$string = preg_replace('/&#(\d+);/me', "chr(\\1)", $string);
$string = preg_replace('/&#x([a-f0-9]+);/mei',"chr(0x\\1)",$string);
// get the stringy UTF-8 stuff
return $string;
}
}
function nextQuote($string, $offset = 0) {
$next = strcspn($string, '"\'', $offset) + $offset;
return strlen($string) == $next ? false : $next;
}
function nextWhiteSpace($string, $offset = 0) {
$next = strcspn($string, "\x20\x09\x0D\x0A", $offset) + $offset;
return strlen($string) == $next ? false : $next;
}
function tokenizeHTML($string) {
// some quick checking (if empty, return empty)
$string = @ (string) $string;
if ($string == '') return array();
$cursor = 0; // our location in the text
$inside_tag = false; // whether or not we're parsing the inside of a tag
$array = array(); // result array
// infinite loop protection
// has to be pretty big, since html docs can be big
// we're allow two hundred thousand tags... more than enough?
$loops = 0;
while(true) {
// infinite loop protection
if (++$loops > 200000) return array();
$position_next_lt = strpos($string, '<', $cursor);
$position_next_gt = strpos($string, '>', $cursor);
// triggers on "<b>asdf</b>" but not "asdf <b></b>"
if ($position_next_lt === $cursor) {
$inside_tag = true;
$cursor++;
}
if (!$inside_tag && $position_next_lt !== false) {
// We are not inside tag and there still is another tag to parse
$array[] = new
HTMLPurifier_Token_Text(
html_entity_decode(
substr(
$string, $cursor, $position_next_lt - $cursor
),
ENT_QUOTES
)
);
$cursor = $position_next_lt + 1;
$inside_tag = true;
continue;
} elseif (!$inside_tag) {
// We are not inside tag but there are no more tags
// If we're already at the end, break
if ($cursor === strlen($string)) break;
// Create Text of rest of string
$array[] = new
HTMLPurifier_Token_Text(
html_entity_decode(
substr(
$string, $cursor
),
ENT_QUOTES
)
);
break;
} elseif ($inside_tag && $position_next_gt !== false) {
// We are in tag and it is well formed
// Grab the internals of the tag
$segment = substr($string, $cursor, $position_next_gt-$cursor);
// Check if it's a comment
if (
substr($segment,0,3) == '!--' &&
substr($segment,strlen($segment)-2,2) == '--'
) {
$array[] = new
HTMLPurifier_Token_Comment(
substr(
$segment, 3, strlen($segment) - 5
)
);
$inside_tag = false;
$cursor = $position_next_gt + 1;
continue;
}
// Check if it's an end tag
$is_end_tag = (strpos($segment,'/') === 0);
if ($is_end_tag) {
$type = substr($segment, 1);
$array[] = new HTMLPurifier_Token_End($type);
$inside_tag = false;
$cursor = $position_next_gt + 1;
continue;
}
// Check if it is explicitly self closing, if so, remove
// trailing slash. Remember, we could have a tag like <br>, so
// any later token processing scripts must convert improperly
// classified EmptyTags from StartTags.
$is_self_closing= (strpos($segment,'/') === strlen($segment)-1);
if ($is_self_closing) {
$segment = substr($segment, 0, strlen($segment) - 1);
}
// Check if there are any attributes
$position_first_space = $this->nextWhiteSpace($segment);
if ($position_first_space === false) {
if ($is_self_closing) {
$array[] = new HTMLPurifier_Token_Empty($segment);
} else {
$array[] = new HTMLPurifier_Token_Start($segment);
}
$inside_tag = false;
$cursor = $position_next_gt + 1;
continue;
}
// Grab out all the data
$type = substr($segment, 0, $position_first_space);
$attribute_string =
trim(
substr(
$segment, $position_first_space
)
);
if ($attribute_string) {
$attributes = $this->tokenizeAttributeString(
$attribute_string
);
} else {
$attributes = array();
}
if ($is_self_closing) {
$array[] = new HTMLPurifier_Token_Empty($type, $attributes);
} else {
$array[] = new HTMLPurifier_Token_Start($type, $attributes);
}
$cursor = $position_next_gt + 1;
$inside_tag = false;
continue;
} else {
$array[] = new
HTMLPurifier_Token_Text(
'<' .
html_entity_decode(
substr($string, $cursor),
ENT_QUOTES
)
);
break;
}
break;
}
return $array;
}
function tokenizeAttributeString($string) {
$string = (string) $string; // quick typecast
if ($string == '') return array(); // no attributes
// let's see if we can abort as quickly as possible
// one equal sign, no spaces => one attribute
$num_equal = substr_count($string, '=');
$has_space = strpos($string, ' ');
if ($num_equal === 0 && !$has_space) {
// bool attribute
return array($string => $string);
} elseif ($num_equal === 1 && !$has_space) {
// only one attribute
list($key, $quoted_value) = explode('=', $string);
$quoted_value = trim($quoted_value);
if (!$key) return array();
if (!$quoted_value) return array($key => '');
$first_char = @$quoted_value[0];
$last_char = @$quoted_value[strlen($quoted_value)-1];
$same_quote = ($first_char == $last_char);
$open_quote = ($first_char == '"' || $first_char == "'");
if ( $same_quote && $open_quote) {
// well behaved
$value = substr($quoted_value, 1, strlen($quoted_value) - 2);
} else {
// not well behaved
if ($open_quote) {
$value = substr($quoted_value, 1);
} else {
$value = $quoted_value;
}
}
return array($key => $value);
}
// setup loop environment
$array = array(); // return assoc array of attributes
$cursor = 0; // current position in string (moves forward)
$size = strlen($string); // size of the string (stays the same)
// if we have unquoted attributes, the parser expects a terminating
// space, so let's guarantee that there's always a terminating space.
$string .= ' ';
// infinite loop protection
$loops = 0;
while(true) {
// infinite loop protection
if (++$loops > 1000) return array();
if ($cursor >= $size) {
break;
}
$cursor += ($value = strspn($string, "\x20\x09\x0D\x0A", $cursor));
$position_next_space = $this->nextWhiteSpace($string, $cursor);
$position_next_equal = strpos($string, '=', $cursor);
// grab the key
$key_begin = $cursor; //we're currently at the start of the key
// scroll past all characters that are the key (not whitespace or =)
$cursor += strcspn($string, "\x20\x09\x0D\x0A=", $cursor);
$key_end = $cursor; // now at the end of the key
$key = substr($string, $key_begin, $key_end - $key_begin);
if (!$key) continue; // empty key
// scroll past all whitespace
$cursor += strspn($string, "\x20\x09\x0D\x0A", $cursor);
if ($cursor >= $size) {
$array[$key] = $key;
break;
}
// if the next character is an equal sign, we've got a regular
// pair, otherwise, it's a bool attribute
$first_char = @$string[$cursor];
if ($first_char == '=') {
// key="value"
$cursor++;
$cursor += strspn($string, "\x20\x09\x0D\x0A", $cursor);
// we might be in front of a quote right now
$char = @$string[$cursor];
if ($char == '"' || $char == "'") {
// it's quoted, end bound is $char
$cursor++;
$value_begin = $cursor;
$cursor = strpos($string, $char, $cursor);
$value_end = $cursor;
} else {
// it's not quoted, end bound is whitespace
$value_begin = $cursor;
$cursor += strcspn($string, "\x20\x09\x0D\x0A", $cursor);
$value_end = $cursor;
}
$value = substr($string, $value_begin, $value_end - $value_begin);
$array[$key] = $value;
$cursor++;
} else {
// boolattr
if ($key !== '') {
$array[$key] = $key;
}
}
}
return $array;
}
}
?>