<?php

// $Id: xrds.inc,v 1.2 2007/10/15 09:40:42 goba Exp $

// Global variables to track parsing state

$xrds_open_elements = array();

$xrds_services = array();

$xrds_current_service = array();

/**

 * Main entry point for parsing XRDS documents

 */

function xrds_parse($xml) {

  global $xrds_services;

  $parser = xml_parser_create_ns();

  xml_set_element_handler($parser, '_xrds_element_start', '_xrds_element_end');

  xml_set_character_data_handler($parser, '_xrds_cdata');

  xml_parse($parser, $xml);

  xml_parser_free($parser);

  return $xrds_services;

}

/**

 * Parser callback functions

 */

function _xrds_element_start(&$parser, $name, $attribs) {

  global $xrds_open_elements;

  $xrds_open_elements[] = _xrds_strip_namespace($name);

}

function _xrds_element_end(&$parser, $name) {

  global $xrds_open_elements, $xrds_services, $xrds_current_service;

  $name = _xrds_strip_namespace($name);

  if ($name == 'SERVICE') {

    if (in_array(OPENID_NS_2_0 .'/signon', $xrds_current_service['types']) ||

        in_array(OPENID_NS_2_0 .'/server', $xrds_current_service['types'])) {

      $xrds_current_service['version'] = 2;

    }

    elseif (in_array(OPENID_NS_1_1, $xrds_current_service['types']) ||

            in_array(OPENID_NS_1_0, $xrds_current_service['types'])) {

      $xrds_current_service['version'] = 1;

    }

    if (!empty($xrds_current_service['version'])) {

      $xrds_services[] = $xrds_current_service;

    }

    $xrds_current_service = array();

  }

  array_pop($xrds_open_elements);

}

function _xrds_cdata(&$parser, $data) {

  global $xrds_open_elements, $xrds_services, $xrds_current_service;

  $path = strtoupper(implode('/', $xrds_open_elements));

  switch ($path) {

    case 'XRDS/XRD/SERVICE/TYPE':

      $xrds_current_service['types'][] = $data;

      break;

    case 'XRDS/XRD/SERVICE/URI':

      $xrds_current_service['uri'] = $data;

      break;

    case 'XRDS/XRD/SERVICE/DELEGATE':

      $xrds_current_service['delegate'] = $data;

      break;

    case 'XRDS/XRD/SERVICE/LOCALID':

      $xrds_current_service['localid'] = $data;

      break;

  }

}

function _xrds_strip_namespace($name) {

  // Strip namespacing.

  $pos = strrpos($name, ':');

  if ($pos !== FALSE) {

    $name = substr($name, $pos + 1, strlen($name));

  }

  return $name;

}