Read layers with available map key from config/key.yml

app/assets/javascripts/osm.js.erb

@@ -1,5 +1,6 @@
 //= depend_on settings.yml
 //= depend_on settings.local.yml
+//= depend_on key.yml
 //= require qs/dist/qs
 
 OSM = {
@@ -29,6 +30,8 @@ OSM = {
   TRACESTRACK_KEY:         <%= Settings.tracestrack_key.to_json %>,
 <% end %>
 
+  LAYERS_WITH_MAP_KEY:     <%= YAML.load_file(Rails.root.join("config/key.yml")).keys.to_json %>,
+
   MARKER_GREEN:            <%= image_path("marker-green.png").to_json %>,
   MARKER_RED:              <%= image_path("marker-red.png").to_json %>,