How do you use gmaps4rails to send a an ajax call using UJS in Ruby on Rails?

Question

I followed the examples in the two locations:

• https://github.com/apneadiving/Google-Maps-for-Rails/wiki/Using-with-UJS
• https://gist.github.com/1643990

but they both do not work. I get nothing back for either. I'm currently using the 1.5.5 version of gmaps4rails in RoR 3.2.8.

show_map.js.erb

$('#map_container').show();
$('#map_container').html('<%= escape_javascript( gmaps({:last_map => false}) ) %>');
Gmaps.map = new Gmaps4RailsGoogle();

Gmaps.load_map = function() {
  Gmaps.map.map_options.maxZoom = 15;
  Gmaps.map.initialize();
  Gmaps.map.create_markers();
  Gmaps.map.adjustMapToBounds();
  Gmaps.map.markers = <%= @json %>;
  Gmaps.map.callback();
};
Gmaps.loadMaps();

users_controller.rb

  def show_map
    @user = User.first
    @json = @user.to_gmaps4rails
    respond_to do |format|
      format.js {}
    end
  end

show.html.haml

  = link_to "Map", show_map_path, :remote => true
  #map_container{:style => 'display:none;'}

Thanks for your help!

Answer 1

I have the same issue as @persistence , and I prefer to report in this thread. I tried to follow both the wiki example first and then sticked to @apneadiving comment and followed your gist, but still I'm missing something from the gist. I place this code in my controller:

events_controller

def index
    @json = Event.all.to_gmaps4rails do |event, marker|
        marker.title        event.title
        marker.infowindow   event.description
        marker.sidebar      'This is a side bar'
    end
    p @json
    respond_with @json
end

And in my view I paste the exact code of the gist. When I push the load button I check in console that my json info is OK, but the map is not loading due to a Javascript error:

TypeError: Gmaps.map is undefined

I guess I'm missing some kind of Javascript initialization of the map?.

UPDATED 05/11/2012:

That was the problem indeed. Combining the javascript from both the gist and wiki example I made this work by putting the following code in the view:

index_view

<!-- create html + load js files but don't create map itself: will be done after ajax call -->
<%= gmaps({:last_map => false}) %>
<br/>

<!-- button to trigger ajax call -->
<button type="button" id="ajax">Load Map</button>

<script type="text/javascript" charset="utf-8">
$(function() {

    //hide the empty container
    $(".map_container").hide();

    // Map initialization
    Gmaps.map = new Gmaps4RailsGoogle();
    Gmaps.load_map = function() {
         Gmaps.map.map_options.maxZoom = 15;
         Gmaps.map.initialize();
         Gmaps.map.create_markers();
         Gmaps.map.adjustMapToBounds();
         Gmaps.map.callback();
    };

    $("#ajax").click(function(){
         $.getJSON('/events', function(json){
              $(".map_container").show();
              Gmaps.loadMaps();
              Gmaps.map.addMarkers(json);
         })
    })
});
</script>

I also left some simple examples of loading Gmaps4Rails maps in GitHub: https://github.com/daviddefco/Gmaps4RailsSamples.git

1. Using and HTML partial
2. Using an AJAX request triggered by an HTML button (gist example)
3. Using an AJAX request inside a Javascript action (wiki example)

I'm a RoR and Javascript newbie, so comments or code improvements are welcome.