box_bound.rb

module BoxBound
  extend ActiveSupport::Concern

  def get_bounds
    curl = Curl::Easy.new
    curl.url = 'http://cartografia.ife.org.mx/sige/ajax/get_searchv5'
    curl.headers = {'Content-Type' => 'application/x-www-form-urlencoded'}
    curl.http_post("e=6&q=#{section}&t=seccion&c=SECCION")
    Yajl::Parser.parse(curl.body.split('|')[1])
  end

  def multipolygon
    @response ||= get_bounds
    @response['valores'].first['geom']
  end

  def bound_coords
    @factory ||= GeoRuby::SimpleFeatures::GeometryFactory.new
    @ewkt_parser ||= GeoRuby::SimpleFeatures::EWKTParser.new @factory
    @ewkt_parser.parse multipolygon
    @coords ||= @factory.geometry.geometries.first.rings.first.map {|point| [point.y, point.x]}
  end
end

maps.js

<script type="text/javascript" charset="utf-8" async defer>
  var map;
  var sections = [<%= @report.near_boxes.map{|near_box| "'#{near_box.section}'"}.join(',').html_safe %>];

  function initialize() {
    var mapOptions = {
      zoom: 14,
      center: new google.maps.LatLng(<%= @geographic_center.first %>, <%= @geographic_center.last %>),
      mapTypeId: google.maps.MapTypeId.ROADMAP,
      styles: [
            {
              "featureType":"administrative",
              "elementType":"labels",
              "stylers":[
                {
                  "visibility":"on"
                }
              ]
            },
            {
              "featureType":"road",
              "stylers":[
                {
                  "visibility":"on"
                }
              ]
            },
            {
              "featureType":"road.highway",
              "stylers":[
                {
                  "visibility":"off"
                }
              ]
            },
            {
              "featureType":"poi",
              "stylers":[
                {
                  "visibility":"off"
                }
              ]
            },
            {
              "featureType":"water",
              "elementType":"labels",
              "stylers":[
                {
                  "visibility":"off"
                }
              ]
            },
            {
              "featureType": "landscape",
              "elementType": "geometry",
              "stylers": [
                { "visibility": "on" },
                { "color": "#ffffff" }
              ]
            }
          ]
    };

    map = new google.maps.Map(document.getElementById('report-map'), mapOptions);

    var boxes_bounds = [<%= @boxes_bound_coords.map do |box_bound|
      "[" + box_bound.map do |coords|
        "new google.maps.LatLng(#{coords.first}, #{coords.last})"
      end.join(',') + "]"
    end.join(',').html_safe %>]

    var color_bound = ['#FF0000', '#00FF00', '#0000FF', '#FFFF00', '#FF00FF']

    for (var i = 0; i < boxes_bounds.length; i++) {
      seccionPolygon = new google.maps.Polygon({
        paths: boxes_bounds[i],
        strokeColor: '#CCCCCC',
        strokeOpacity: 0.8,
        strokeWeight: 2,
        fillColor: color_bound[i],
        fillOpacity: 0.15
      });

      seccionPolygon.setMap(map);
    }
  }

  google.maps.event.addDomListener(window, 'load', initialize);
</script>