Dibujar múltiples polígonos en Google Maps API v3 desde la base de datos MySQL

El google.maps.Polygon La propiedad paths toma una matriz de matrices de google.maps.LatLngs. Debe procesar cada subdivisión como su propia matriz y empujarla como una ruta separada en un polígono o (como se muestra a continuación) crear un nuevo polígono para cada uno.

    var subdivision = xml.getElementsByTagName("subdivision");
    for (var i = 0; i < subdivision.length; i++) {
        arr = [];
        var coordinates = xml.documentElement.getElementsByTagName("subdivision")[i].getElementsByTagName("coord");
        for (var j=0; j < coordinates.length; j++) {
          arr.push( new google.maps.LatLng(
                parseFloat(coordinates[j].getAttribute("lat")),
                parseFloat(coordinates[j].getAttribute("lng"))
          ));
            
          bounds.extend(arr[arr.length-1])
        }
        polygons.push(new google.maps.Polygon({
            paths: arr,
            strokeColor: '#FF0000',
            strokeOpacity: 0.8,
            strokeWeight: 2,
            fillColor: '#FF0000',
            fillOpacity: 0.35
        }));
        polygons[polygons.length-1].setMap(map);
    }

violín de trabajo

fragmento de código:

function initialize() {
  var mapOptions = {
    zoom: 5,
    center: new google.maps.LatLng(40, -117),
    mapTypeId: google.maps.MapTypeId.ROADMAP
  };

  var map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
  var arr = new Array();
  var polygons = [];
  var bounds = new google.maps.LatLngBounds();

  // downloadUrl("subdivision-coordinates.php", function(data) {
  var xml = xmlParse(xmlString);
  var subdivision = xml.getElementsByTagName("subdivision");
  // alert(subdivision.length);
  for (var i = 0; i < subdivision.length; i++) {
    arr = [];
    var coordinates = xml.documentElement.getElementsByTagName("subdivision")[i].getElementsByTagName("coord");
    for (var j = 0; j < coordinates.length; j++) {
      arr.push(new google.maps.LatLng(
        parseFloat(coordinates[j].getAttribute("lat")),
        parseFloat(coordinates[j].getAttribute("lng"))
      ));

      bounds.extend(arr[arr.length - 1])
    }
    polygons.push(new google.maps.Polygon({
      paths: arr,
      strokeColor: '#FF0000',
      strokeOpacity: 0.8,
      strokeWeight: 2,
      fillColor: '#FF0000',
      fillOpacity: 0.35
    }));
    polygons[polygons.length - 1].setMap(map);
  }
  // });
  map.fitBounds(bounds);
}
var xmlString = '<subdivisions><subdivision name="Auburn Hills"><coord lat="39.00748" lng="-92.323222"/><coord lat="39.000843" lng="-92.323523"/><coord lat="39.000509" lng="-92.311592"/><coord lat="39.007513" lng="-92.311378"/><coord lat="39.00748" lng="-92.323222"/></subdivision><subdivision name="Vanderveen"><coord lat="38.994206" lng="-92.350645"/><coord lat="38.985033" lng="-92.351074"/><coord lat="38.984699" lng="-92.343092"/><coord lat="38.981163" lng="-92.342234"/><coord lat="38.984663" lng="-92.3335"/><coord lat="38.993472" lng="-92.333179"/><coord lat="38.994206" lng="-92.350645"/></subdivision><subdivisions>';

/**
 * Parses the given XML string and returns the parsed document in a
 * DOM data structure. This function will return an empty DOM node if
 * XML parsing is not supported in this browser.
 * @param {string} str XML string.
 * @return {Element|Document} DOM.
 */
function xmlParse(str) {
  if (typeof ActiveXObject != 'undefined' && typeof GetObject != 'undefined') {
    var doc = new ActiveXObject('Microsoft.XMLDOM');
    doc.loadXML(str);
    return doc;
  }

  if (typeof DOMParser != 'undefined') {
    return (new DOMParser()).parseFromString(str, 'text/xml');
  }

  return createElement('div', null);
}

google.maps.event.addDomListener(window, 'load', initialize);

#map-canvas,
body,
html {
  height: 100%;
  width: 100%;
}

<script src="http://maps.google.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk"></script>
<div id="map-canvas"></div>