Tie legacy analytics ID to environment

app/controllers/application_controller.rb

@@ -1,5 +1,6 @@
 class ApplicationController < ActionController::Base
   protect_from_forgery with: :exception, prepend: true
+  before_action :set_google_analytics_id
 
 
   def verify_admin
@@ -16,4 +17,9 @@ class ApplicationController < ActionController::Base
     end
   end
 
+  private
+  def set_google_analytics_id
+    @google_analytics_id = ENV['GOOGLE_ANALYTICS_ID']
+  end
+
 end

app/views/layouts/application.html.haml

@@ -13,13 +13,13 @@
     = javascript_include_tag 'application', 'data-turbolinks-track': 'reload'
 
     / Global site tag (gtag.js) - Google Analytics
-    %script{:async => "", :src => "https://www.googletagmanager.com/gtag/js?id=UA-132936999-1"}
+    %script{:async => "", :src => "https://www.googletagmanager.com/gtag/js?id=#{@google_analytics_id}"}
     :javascript
       window.dataLayer = window.dataLayer || [];
       function gtag(){dataLayer.push(arguments);}
       gtag('js', new Date());
 
-      gtag('config', 'UA-132936999-1');
+      gtag('config', #{@google_analytics_id.to_json.html_safe});
 
   %body
     .container

app/views/layouts/home.html.erb

@@ -7,7 +7,7 @@
   <%= stylesheet_link_tag 'welcome', media: 'all', 'data-turbolinks-track': 'reload' %>
   <%= javascript_include_tag 'application', 'data-turbolinks-track': 'reload' %>
   <!-- Global site tag (gtag.js) - Google Analytics -->
-  <script src="https://www.googletagmanager.com/gtag/js?id=<%= @google_analytics_id %>" type="javascript"></script>
+  <script async src="https://www.googletagmanager.com/gtag/js?id=<%= @google_analytics_id %>" type="javascript"></script>
   <script type="javascript">
     window.dataLayer = window.dataLayer || [];