<?php
# Relative URI static class: PHP class for resolving relative URLs
#
# This class is derived (under the terms of the GPL) from URL Class 0.3 by
# Keyvan Minoukadeh <[email protected]>, which is great but more than we need
# for FeedWordPress's purposes. The class has been stripped down to a single
# public method: Relative_URI::resolve($url, $base), which resolves the URI in
# $url relative to the URI in $base
class Relative_URI
{
// Resolve relative URI in $url against the base URI in $base. If $base
// is not supplied, then we use the REQUEST_URI of this script.
//
// I'm hoping this method reflects RFC 2396 Section 5.2
function resolve ($url, $base = NULL)
{
if (is_null($base)):
$base = 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
endif;
$base = Relative_URI::_encode(trim($base));
$uri_parts = Relative_URI::_parse_url($base);
$url = Relative_URI::_encode(trim($url));
$parts = Relative_URI::_parse_url($url);
$uri_parts['fragment'] = (isset($parts['fragment']) ? $parts['fragment'] : null);
$uri_parts['query'] = (isset($parts['query']) ? $parts['query'] : null);
// if path is empty, and scheme, host, and query are undefined,
// the URL is referring the base URL
if (($parts['path'] == '') && !isset($parts['scheme']) && !isset($parts['host']) && !isset($parts['query'])) {
// If the URI is empty or only a fragment, return the base URI
return $base . (isset($parts['fragment']) ? '#'.$parts['fragment'] : '');
} elseif (isset($parts['scheme'])) {
// If the scheme is set, then the URI is absolute.
return $url;
} elseif (isset($parts['host'])) {
$uri_parts['host'] = $parts['host'];
$uri_parts['path'] = $parts['path'];
} else {
// We have a relative path but not a host.
// start ugly fix:
// prepend slash to path if base host is set, base path is not set, and url path is not absolute
if ($uri_parts['host'] && ($uri_parts['path'] == '')
&& (strlen($parts['path']) > 0)
&& (substr($parts['path'], 0, 1) != '/')) {
$parts['path'] = '/'.$parts['path'];
} // end ugly fix
if (substr($parts['path'], 0, 1) == '/') {
$uri_parts['path'] = $parts['path'];
} else {
// copy base path excluding any characters after the last (right-most) slash character
$buffer = substr($uri_parts['path'], 0, (int)strrpos($uri_parts['path'], '/')+1);
// append relative path
$buffer .= $parts['path'];
// remove "./" where "." is a complete path segment.
$buffer = str_replace('/./', '/', $buffer);
if (substr($buffer, 0, 2) == './') {
$buffer = substr($buffer, 2);
}
// if buffer ends with "." as a complete path segment, remove it
if (substr($buffer, -2) == '/.') {
$buffer = substr($buffer, 0, -1);
}
// remove "<segment>/../" where <segment> is a complete path segment not equal to ".."
$search_finished = false;
$segment = explode('/', $buffer);
while (!$search_finished) {
for ($x=0; $x+1 < count($segment);) {
if (($segment[$x] != '') && ($segment[$x] != '..') && ($segment[$x+1] == '..')) {
if ($x+2 == count($segment)) $segment[] = '';
unset($segment[$x], $segment[$x+1]);
$segment = array_values($segment);
continue 2;
} else {
$x++;
}
}
$search_finished = true;
}
$buffer = (count($segment) == 1) ? '/' : implode('/', $segment);
$uri_parts['path'] = $buffer;
}
}
// If we've gotten to this point, we can try to put the pieces
// back together.
$ret = '';
if (isset($uri_parts['scheme'])) $ret .= $uri_parts['scheme'].':';
if (isset($uri_parts['user'])) {
$ret .= $uri_parts['user'];
if (isset($uri_parts['pass'])) $ret .= ':'.$uri_parts['parts'];
$ret .= '@';
}
if (isset($uri_parts['host'])) {
$ret .= '//'.$uri_parts['host'];
if (isset($uri_parts['port'])) $ret .= ':'.$uri_parts['port'];
}
$ret .= $uri_parts['path'];
if (isset($uri_parts['query'])) $ret .= '?'.$uri_parts['query'];
if (isset($uri_parts['fragment'])) $ret .= '#'.$uri_parts['fragment'];
return $ret;
}
/**
* Parse URL
*
* Regular expression grabbed from RFC 2396 Appendix B.
* This is a replacement for PHPs builtin parse_url().
* @param string $url
* @access private
* @return array
*/
function _parse_url($url)
{
// I'm using this pattern instead of parse_url() as there's a few strings where parse_url()
// generates a warning.
if (preg_match('!^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?!', $url, $match)) {
$parts = array();
if ($match[1] != '') $parts['scheme'] = $match[2];
if ($match[3] != '') $parts['auth'] = $match[4];
// parse auth
if (isset($parts['auth'])) {
// store user info
if (($at_pos = strpos($parts['auth'], '@')) !== false) {
$userinfo = explode(':', substr($parts['auth'], 0, $at_pos), 2);
$parts['user'] = $userinfo[0];
if (isset($userinfo[1])) $parts['pass'] = $userinfo[1];
$parts['auth'] = substr($parts['auth'], $at_pos+1);
}
// get port number
if ($port_pos = strrpos($parts['auth'], ':')) {
$parts['host'] = substr($parts['auth'], 0, $port_pos);
$parts['port'] = (int)substr($parts['auth'], $port_pos+1);
if ($parts['port'] < 1) $parts['port'] = null;
} else {
$parts['host'] = $parts['auth'];
}
}
unset($parts['auth']);
$parts['path'] = $match[5];
if (isset($match[6]) && ($match[6] != '')) $parts['query'] = $match[7];
if (isset($match[8]) && ($match[8] != '')) $parts['fragment'] = $match[9];
return $parts;
}
// shouldn't reach here
return array('path'=>'');
}
function _encode($string)
{
static $replace = array();
if (!count($replace)) {
$find = array(32, 34, 60, 62, 123, 124, 125, 91, 92, 93, 94, 96, 127);
$find = array_merge(range(0, 31), $find);
$find = array_map('chr', $find);
foreach ($find as $char) {
$replace[$char] = '%'.bin2hex($char);
}
}
// escape control characters and a few other characters
$encoded = strtr($string, $replace);
// remove any character outside the hex range: 21 - 7E (see www.asciitable.com)
return preg_replace('/[^\x21-\x7e]/', '', $encoded);
}
} // class Relative_URI
