Meerdere polygonen tekenen op Google Maps API v3 vanuit MySQL-database

De google.maps.Polygon paths heeft een array van arrays van google.maps.LatLngs nodig. Je moet elke onderverdeling als zijn eigen array verwerken en deze ofwel als een apart pad in de ene polygoon duwen of (zoals hieronder) een nieuwe polygoon voor elke polygoon maken.

    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);
    }

werkende viool

codefragment:

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>