javascript google maps geocoder initialize

Question

I am trying to use the google maps javascript API to map an address based on this example.

https://google-developers.appspot.com/maps/documentation/javascript/examples/geocoding-simple

The documentation recommends the clientside javascript approach as the best way to deal with quotas on requests. So far so good. My problem is in moving from this example to my specific case. My addresses are already in a database so I don't need the user to enter one. Also I do not want the map to load with the page. Instead, I want the map for the address to load when the user clicks a link.

I have a script working that loads the map in a div using initialize (). But my problem is getting initialize to work with geocode. The geocode in the example depends on initialize loading with bodyonload which I do not want.

Here is code. Would appreciate any suggestions:

javascript

    var map;
    var geocoder;


     function codeAddress() {
            var address = document.getElementById('address').value;
            geocoder.geocode( { 'address': address}, function(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);
              }
            });
          }

      function initialize() {
    geocoder = new google.maps.Geocoder();
        var latlng = new google.maps.LatLng(40.7562008,-73.9903784);
        var myOptions = {
          zoom: 18,
          center: latlng,
          mapTypeId: google.maps.MapTypeId.ROADMAP
        };
        var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
      }

html

<input id="address" type="hidden" value="Palo Alto CA">
<a href="javascript:void(0)" onclick="initialize()">View map without geocoding</a>
<div id="map_canvas" style="width:300px; height:300px;"></div>
<a href="javascript:void(0)" onclick="codeAddress()">View map of geocoded address</a>

Answer 1

The only issue I had with your script was the following line in the initialize() function:

var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);

By declaring var map , your script is just declaring a local variable named map , as opposed to using the global map variable declared at the top of your script.

By removing var , the script uses the global variable and runs fine:

map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);

Finally, to get the geocoded map to load on the link click, change onclick for your geocoded address to onclick="initialize();codeAddress();" .

Added:

Try combining your initialize() and codeAddress() methods into the following:

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

    var address = document.getElementById('address').value;
    geocoder.geocode({ 'address': address }, function (results, status) {
        if (status == google.maps.GeocoderStatus.OK) {
            var myOptions = {
                zoom: 18,
                center: results[0].geometry.location,
                mapTypeId: google.maps.MapTypeId.ROADMAP
            };
            map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
        } else {
            alert('Geocode was not successful for the following reason: ' + status);
        }
    });
}

And then just call initialize() from your link.

Basically, what we're doing is taking the call to geocoder.geocode() that codeAddress() was performing and inside the resulting delegate, we're using results[0].geometry.location to initialize the map. This way, the temporary latlong doesn't need to be displayed.