Question

My javascript function getLatLng works great when called by the window.onload. But when I use the handler to call it I get a position (NaN, NaN) from the geocoder.

Why doesn’t it work when I click the submit button but works great from the window.onload?

<script type="text/javascript"
  src="http://maps.googleapis.com/maps/api/js?key=MYSECRETKEYHERE&sensor=false">
</script>    

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js" type="text/javascript"></script>


<form id="update_info" method="post" action="{{upload_url}}" enctyp="multipart/form-data">
<input name="address" id="address" type="text" value="100 W Main St Lehi, UT"/>
<input name="latlng" id = "latlng" type="text" value=""/>
<input name="update_reseller_button" id="update_reseller_button" type="submit">
</form>


<script>

function getLatLng()
{
    var geocoder = new google.maps.Geocoder();

    var theaddress = document.getElementById('address').value;
    var position = new google.maps.LatLng();

    geocoder.geocode({'address': theaddress}, function(results, status
      )
    {                       
        position = results[0].geometry.location;                  
        document.getElementById('latlng').value = position.toString();
    });
    return position;
}

$('#update_info').submit(function()

  {
    alert('The Position is: ' +  getLatLng().toString());
    return true;
  });

  window.onload = getLatLng();

</script>

EDIT: Fixed typo in the handler pointing to the wrong form

EDIT 2: Fixed more typos

EDIT 3: Changed so alert shows the value of position

Answer 1

your getLatLng-function will never work as expected, it will never return the result of the geocoding, because geocoding is an asynchronous request.

This:

window.onload = getLatLng();

…will call the function(not onload, immediately), and the function will execute the instructions, but will also return (NaN, NaN)