Gmaps4Rails not displaying markers

Question

I'm trying to use the Gmaps4Rails gem to display a number of markers using their lat / long coordinates.

I have a Locations model with two attributes i.e., 'latitude' and 'longitude'. In my controller, I have the following method:

def display
    @locations = Location.all       

    @hash = Gmaps4rails.build_markers(@locations) do |location, marker|
      marker.lat location.latitude
      marker.lng location.longitude
    end

    p @hash.inspect

  end

When I look in the logs, the hash with all of the Location objects' lat & long coordinates appears to be correct.

In the view, I have the following:

<div style='width: 800px;'>
  <div id="map" style='width: 1200px; height: 740px;'></div>
</div>

<script type="text/javascript">
    handler = Gmaps.build('Google');
    handler.buildMap({ provider: {}, internal: {id: 'map'}}, function(){
      markers = handler.addMarkers(<%= raw(@hash.to_json) %>);
      handler.bounds.extendWith(markers);
      handler.fitMapToBounds();
    });
</script>

When I load the view, I see the following but when I zoom in or out, the background becomes opaque.

Any thoughts?

Answer 1

As mentioned in comment, google maps crashes when coordinates are null.

You need to create a scope on your model yo only fetch valid geocoded objects.