Is there a way to add current location marker to gmaps4rails?

Question

I'm trying to figure out how to add a current location marker to gmaps4rails map along with some map_points from the backend using @map_points = @user.places.to_gmaps4rails. I saw the following post:

How do I display the user's location with a marker in gmaps4rails?

and tried to implement the javascript there, but it doesn't seem to be working. I added this code to my javascript section, but for some reason the callback doesn't seem to be firing:

= gmaps("map_options" => {"detect_location" => true, "center_on_user" => true, "auto_zoom" => false, "zoom" => 12, "auto_adjust" => true, "markers" => {"data" => @map_points}})

:javascript
  Gmaps.map.callback = function() {
    Gmaps.map.addMarkers({Lat: Gmaps.map.userLocation.lat(), Lng: Gmaps.map.userLocation.lng(), rich_marker: null, marker_picture:""});
    }

EDIT: here's what I have now, but for some reason the addListenerOnce isn't firing:

- content_for :scripts do
  :javascript
    Gmaps.map.callback = function() {
      google.maps.event.addListenerOnce(Gmaps.map.getMapObject(),'idle', function(){
        navigator.geolocation.getCurrentPosition(add_map_marker,displayError);
      });

    };

    function add_map_marker(position){
      var lat = position.coords.latitude;
      var lng = position.coords.longitude;
      Gmaps.map.addMarkers([{
        "lng": lng,
        "lat": lat,
        "picture": "http://googlemaps.googlermania.com/google_maps_api_v3/en/Google_Maps_Marker.png",
        "width": "37",
        "height": "34"
      }]);
    }

    function displayError(error){
      alert('There is an error displaying location');
    }

apneadiving · Accepted Answer · 2012-11-25T11:27:33.950

2

You should use the addMarkers defined here.

You should pass a json array of markers as an argument, resulting from a to_gmaps4rails or with the same format.

Edit:

:javascript
  Gmaps.map.callback = function() {
    Gmaps.map.addMarkers([
      {"description": "", "title": "", "sidebar": "", "lng": "", "lat": "", "picture": "", "width": "", "height": ""}
    ]);
  }

If ever map doesn't exist yet, look here.

edited Nov 25 '12 at 11:27

answered Nov 24 '12 at 20:23

apneadiving

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Thanks for the help, how exactly would I implement this in my `show` view? – locoboy Nov 24 '12 at 23:45
The problem here is how do I get the current lat, lng? I tried `Gmaps.map.userLocation.lat()` for latitude, but it doesn't work...See my code above. Also I noticed when I call this callback all the points from the `=gmaps(blah, :data=>@map_points)` call get wiped out. – locoboy Nov 25 '12 at 19:10
Use the callback dedicated for after geolocation success – apneadiving Nov 25 '12 at 22:06
is that the same callback that you have above? Should i just render all the places and the current position in js? – locoboy Nov 26 '12 at 01:30

score 1 · Answer 2 · answered Nov 24 '12 at 11:12

Where exactly you added that code? because I think without some reload such as:

Gmaps.loadMaps();

it will not work anyway... to solve that issue I guess you have to describe whole path. How exactly are you loading everything? If standard way, you need reload map.

I would recommend also to take closer look into (gmaps4rails source)

Gmaps4rails::JsBuilder.create_js

method and if it is your default behavior try develop own method with this custom injection for callback (around line 34).

Other way is to call some ajax and with ujs do:

  $('#map').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.markers = <%=raw @json %>;
    Gmaps.map.create_markers();
    Gmaps.map.adjustMapToBounds();
    Gmaps.map.callback();
  };
  Gmaps.loadMaps();

Is there a way to add current location marker to gmaps4rails?

2 Answers2