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Editorial Team
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Asked: 2026-06-06T12:54:33+00:00

I’m parsing XML to get multiple markers directly from the database, so used the

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I’m parsing XML to get multiple markers directly from the database, so used the Google example for this. I now need to show the user’s location on the map (as the centre point). I’m finding either creating a function to load the map after the geolocation tricky, and this is where I am going wrong.

As you can see I can alert the lat & long but as the map loads first, it won’t centre the map on those co-ordinates. I have tried creating a function afterwards to run the map, but I must be missing something.
If anyone could help me that would be great – or even where to move the load function to.

A test page where I am working from is located here: http://www.musecosystems.com/app/event_map2.html

if (navigator.geolocation) 
{
    navigator.geolocation.getCurrentPosition( 

        function (position) {  
    var current_latitude = position.coords.latitude;
    var current_longitude = position.coords.longitude;
    alert ("Latitude"+current_latitude+"Longitude"+current_longitude);mapServiceProvider(position.coords.latitude,position.coords.longitude);
    }   
        );
    } 
 </script><script>



function load() {
      var map = new google.maps.Map(document.getElementById("map"), {

        center: new google.maps.LatLng(54.046575, -2.8007399),
        zoom: 16,
        mapTypeId: 'roadmap'
      });


    var infoWindow = new google.maps.InfoWindow;
          document.getElementById("map").style.width=screen.width+"px";
          document.getElementById("map").style.height=screen.height+"px";
          document.getElementById("map").style.padding="0px";
          document.getElementById("map").style.margin="0px";

      // Change this depending on the name of your PHP file
      downloadUrl("http://www.musecosystems.com/app/server/venue_output.php", function(data) {
        var xml = data.responseXML;
        var markers = xml.documentElement.getElementsByTagName("marker");
        for (var i = 0; i < markers.length; i++) {
          var name = markers[i].getAttribute("name");
          var event_name = markers[i].getAttribute("event_name");
          var event_start = markers[i].getAttribute("event_start");
          var event_link = markers[i].getAttribute("event_link");    
          var type = markers[i].getAttribute("location_status");
          var point = new google.maps.LatLng(
              parseFloat(markers[i].getAttribute("latitude")),
              parseFloat(markers[i].getAttribute("longitude")));
          var html = "<b>" + name + "</b>" + "<br/>" +("<a href='" + event_link + "'>" + event_name + "</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, request.status);
        }
      };

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

    function doNothing() {}


  </script>

  </head>

  <body onload="load()">
    <div id="map" ></div>
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1 Answer

  1. Editorial Team

    I’d try the following:

    …

    <script>
    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition(function (position) {  
            var current_latitude = position.coords.latitude;
            var current_longitude = position.coords.longitude;
            load(current_latitude, current_longitude);
        });
    } else {
        load(54.046575, -2.8007399);
    }
</script>

    …

    function load(center_lat,center_lng) {
    var map = new google.maps.Map(document.getElementById("map"), {
        center: new google.maps.LatLng(center_lat, center_lng),
        zoom: 16,
        mapTypeId: 'roadmap'
});

    …

    <body><div id="map"></div></body>

    By the way: there is a good Firefox extension called Geolocater to test if the geolocation works as expected.

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