Question

I’m sure I’m dealing with a fairly common problem that’s been solved many times before.

My web application requests about 100 line-delimited addresses of buildings from another service. I must now plot all these as gmarkers on a google map (with api version 3). I must also calibrate the view port to display all the gmarkers, that is determine the map center and the appropriate zoom value.

I found some code from the Google Maps API and tweaked it to plot one point:

  function codeAddress() {
    var address = '1 Yonge Street, Toronto, ON'; 
    geocoder.geocode( { 'address': address}, geocodeCallBack);
  }

  function geocodeCallBack(results, status)
  {
      if (status == google.maps.GeocoderStatus.OK) {
        map.setCenter(results[0].geometry.location);
        var marker = new google.maps.Marker({
            map: map,
            position: results[0].geometry.location
        });
      } else {
        alert("Geocode was not successful for the following reason: " + status);
      }

  }

However, I suspect that performing 100 asynchronous geocoding calls may be slow. Does anyone have suggestion on the best way to achieve what I need?

Answer 1

Performing 100 Geocodes each time your page is loaded will take tens of seconds, so I suggest geocoding in advance.

If the addresses are always the same, or rarely change, you can geocode them in advance using the Geocoding Service (http://code.google.com/apis/maps/documentation/javascript/services.html) and temporarily store the resulting Lat/Lngs on your server as long as they are only ever displayed on a Maps API map.

Temporarily means that you must update these Lat/Lngs periodically (e.g. once every 30 days).

(See 10.1.3b for details: http://code.google.com/apis/maps/terms.html)