var customIcons = {
  pays: {
    icon: 'http://maps.google.com/mapfiles/arrow.png',
    shadow: 'http://maps.google.com/mapfiles/arrowshadow.png'
  },
  groupe: {
    icon: 'http://www.google.com/mapfiles/marker.png',
    shadow: 'http://www.google.com/mapfiles/shadow50.png'
  }
};

function load() {
  var map = new google.maps.Map(document.getElementById("map"), {
    center: new google.maps.LatLng(47, 2),
    zoom: 6,
    mapTypeId: 'terrain'
  });
  var infoWindow = new google.maps.InfoWindow;

  // Change this depending on the name of your PHP file
  downloadUrl("groupes-xml.php", function(data) {
    var xml = parseXml(data);
    var markers = xml.documentElement.getElementsByTagName("marker");
    for (var i = 0; i < markers.length; i++) {
      var name = markers[i].getAttribute("nom");
      var address = markers[i].getAttribute("adr");
      var dep = markers[i].getAttribute("dep");
      var type = markers[i].getAttribute("type");
      var point = new google.maps.LatLng(
          parseFloat(markers[i].getAttribute("lat")),
          parseFloat(markers[i].getAttribute("lng")));
      var html = "<strong>" + name + "</strong> (" + dep + ")<br /><a href='" + address + "'>Accès au groupe</a>";
      var icon = customIcons[type] || {};
      var marker = new google.maps.Marker({
        map: map,
        position: point,
        icon: icon.icon,
        shadow: icon.shadow
      });
      bindInfoWindow(marker, map, infoWindow, html);
    }
  });
}

function bindInfoWindow(marker, map, infoWindow, html) {
  google.maps.event.addListener(marker, 'click', function() {
    infoWindow.setContent(html);
    infoWindow.open(map, marker);
  });
}

function downloadUrl(url, callback) {
  var request = window.ActiveXObject ?
      new ActiveXObject('Microsoft.XMLHTTP') :
      new XMLHttpRequest;

  request.onreadystatechange = function() {
    if (request.readyState == 4) {
      request.onreadystatechange = doNothing;
      callback(request.responseText, request.status);
    }
  };

  request.open('GET', url, true);
  request.send(null);
}

function parseXml(str) {
  if (window.ActiveXObject) {
    var doc = new ActiveXObject('Microsoft.XMLDOM');
    doc.loadXML(str);
    return doc;
  } else if (window.DOMParser) {
    return (new DOMParser).parseFromString(str, 'text/xml');
  }
}

function doNothing() {}