如何将JSON数据从控制器传递到JavaScript

Question

In my cluster Table have cluster coordinates column name description, i am directly storing coordinates in Json format like below is my cluster table ,using these coordinates i want to draw multiple cluster(polygons) in google map,

    id |       description                                                                                                                                                                                                
----+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  1 | {"points":[{"lat":14.232437996569354,"lng":76.409912109375},{"lat":13.336175186494927,"lng":77.1185302734375},{"lat":12.961735843534294,"lng":77.596435546875},{"lat":12.511665400971031,"lng":76.904296875}]}


 2   |    {"points":[{"lat":14.232437996569354,"lng":76.409912109375},  {"lat":13.336175186494927,"lng":77.1185302734375},{"lat":12.961735843534294,"lng":77.596435546875},{"lat":12.511665400971031,"lng":76.904296875}]}

I need to draw multiple polygon
but i am trying get this json into rails controller using

controller code

query="select id,description  from clusters;
@result=ActiveRecord::Base.connection.execute(query);

The problem i am facing here how to pass this @result to javascript to draw multiple polygon in google map. if copy this json into one varible in js i able to draw cluster but problem i am facing how pass this json data from database reading in controller to javascript in rails

my google map code in javascript if hard code json into one varible it is working but i need take this json from database how to pass json with id from controller to javascript

var obj=i need json to store here //this how to fetch json from controller to js  
polygons = [];
for(var i = 0; i < obj.length; ++i){
   //do something with obj[i]
   for(var ind in obj[i]) {
        console.log(ind);
          var arr = new google.maps.MVCArray();
        for(var vals in obj[i][ind]){
            console.log(vals, obj[i][ind][vals].lat );
                 arr.push( new google.maps.LatLng( obj[i][ind][vals].lat, obj[i][ind][vals].lng ) );
        }
   }

polygons.push(arr);
}       

    polygons.forEach( function(polyPath) {

        var polygon = new google.maps.Polygon({
            paths: polyPath,
            strokeColor: '#FF0000',
            strokeOpacity: 0.8,
            strokeWeight: 2,
            fillColor: '#FF0000',
            fillOpacity: 0.35,
            map: map
        });
    });
}

google.maps.event.addDomListener(window, 'load', initialize);

Answer 1

I would suggest an ajax-load for points. Then you can use the JSON-Output for rendering the action. It could be:

render json: @result

Other solution: When you have the googlemaps code in your view you could assign a json-string from the db to a javascript-variable:

var json_string = '<%= @results.raw %>';