PHP: Replacement http_build_query

gistfile1.php

<?php

/**
 * Recursive function to work through the data
 *
 * http_build_query in php 5 will screw up array serialisation by encoding the square brackets
 * and make it incompatible for passing to an URL's GET segment or sending through post data manually
 *
 * Thanks to Marco K. (link below), A version intended for php < 5 actually encodes the data correctly
 *
 * @see http://uk.php.net/manual/en/function.http-build-query.php#90438
 * @param array|object $data
 * @param string $prefix
 * @param string $sep
 * @param string $key
 * @return string
 */
function query_string_encode($data, $prefix = '', $sep = '&', $key = '') {
	$ret = array();
	//if it's not an array or object, then it's not iterable (has no keys) so just return it
	if (!is_array($data) && !is_object($data))
		return rawurlencode($data);

	foreach ($data as $k => $v) {
		//cleanup and prepend prefix to the current key
		if ($prefix != null) {
			$k = rawurlencode($prefix . $k);
		}

		//if the key is not empty, it implies it's been called recursively so set up the query string array key
		if ((!empty($key)) || ($key === 0))
			$k = $key . '[' . rawurlencode($k) . ']';

		//now we work on the value
		if (is_array($v)) {
			//just recusively call this function, eventually we'll get all the multidimensional array elements
			//unless some idiot does recursive references, at which point the loop will be infinite
			array_push($ret, query_string_encode($v, '', $sep, $k));
		} elseif (is_object($v)) {
			//handle objects differently. First see if it has the toQueryString method
			if (method_exists($v, 'toQueryString')) {
				$refl = new ReflectionMethod($v, 'toQueryString');

				//the method is valid, so run it
				if ($refl->isPublic() && !$refl->isStatic()) {
					$obj_str = $v->toQueryString('', $sep, $k);
				} else {
					//it's not valid so we need to iterate the object
					$obj_str = $v;
				}
			} else {
				//the method doesn't exist so we need to iterate through it
				$obj_str = $v;
			}

			//it seems it has returned an array or the method wasn't found, so let's iterate through it
			if (is_array($obj_str) || is_object($obj_str)) {
				array_push($ret, $this->_encode($obj_str, '', $sep, $k));
			} else {

				//we had a return value that wasn't an array
				//as the return is from toQueryString which calls this class (everything else is considered an array), we will trust it
				array_push($ret, $k . '=' . $obj_str);
			}
		} else {
			array_push($ret, $k . '=' . rawurlencode($v));
		}
	}

	//set the seperator and implode to create the final string
	if (empty($sep))
		$sep = ini_get('arg_separator.output');
	return implode($sep, $ret);
}