Adding Google Analytics to Rails 4.2 app

I've got a Rails 4.2 app that I've deployed with Heroku and I've tried to add Google Analytics to it. However, Google Analytics isn't picking up any sessions.

Any suggestions why and how to resolve this?

CODE

/app/layouts/_footer.html.erb:

<% if Rails.env.production? %>
  <script>
    (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
    (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
    m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
    })(window,document,'script','//www.google-analytics.com/analytics.js','ga');

    ga('create', 'UA-XXXXXXXX-X', 'herokuapp.com');
    ga('send', 'pageview');

  </script>
<% end %>

/app/layouts/application.html.erb:

<!DOCTYPE html>
<html>
<head>
  <title>Title</title>
<%= Gon::Base.render_data({}) %>
  <%= stylesheet_link_tag    'application', media: 'all', 'data-turbolinks-track' => true %>
  <%= javascript_include_tag 'application', 'data-turbolinks-track' => true %>
  <%= csrf_meta_tags %>
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>

<div class="container">
    <%= yield %>
</div>

<%= render 'layouts/footer' %>

</body>
</html>

/app/assets/javascripts/analytics.js.coffee:

$(document).on 'page:change', ->
 if window._gaq?
  _gaq.push ['_trackPageview']
 else if window.pageTracker?
  pageTracker._trackPageview()

/app/assets/javascripts/application.js:

//= require jquery
//= require analytics
//= require bootstrap
//= require jquery_ujs
//= require jquery.ui.all
//= require Chart
//= require jquery.turbolinks
//= require lodash
//= require_tree .

Gemfile:

source 'https://rubygems.org'

gem 'rails',                '4.2.2'
gem 'bootstrap-sass',       '3.2.0.0'
gem 'sass-rails',           '5.0.2'
gem 'uglifier',             '2.5.3'
gem 'coffee-rails',         '4.1.0'
gem 'jquery-rails',         '4.0.3'
gem 'jquery-ui-rails', '~> 4.2.1'
gem 'turbolinks',           '2.3.0'
gem 'jquery-turbolinks'
gem 'jbuilder',             '2.2.3'
gem 'sdoc',                 '0.4.0', group: :doc
gem 'chart-js-rails'
gem 'gon'
gem 'lodash-rails'

group :development, :test do
  gem 'sqlite3',     '1.3.9'
  gem 'byebug',      '3.4.0'
  gem 'web-console', '2.0.0.beta3'
  gem 'spring',      '1.1.3'
end

group :production do
  gem 'pg',             '0.17.1'
  gem 'rails_12factor', '0.0.2'
end

The way you are adding your script is the wrong way, since it will not work due to Turbolinks, you know the code you have in your _footer won't be running as expected since that piece of markup won't reload because of Turbolinks.

I will give you my custom implementation of google analytics for all my rails apps.

In your app/assets/javascripts create a new file called google_analytics.js.coffee and add the following script:

class @GoogleAnalytics

  @load: ->
    # Google Analytics depends on a global _gaq array. window is the global scope.
    window._gaq = []
    window._gaq.push ["_setAccount", GoogleAnalytics.analyticsId()]

    # Create a script element and insert it in the DOM
    ga = document.createElement("script")
    ga.type = "text/javascript"
    ga.async = true
    ga.src = ((if "https:" is document.location.protocol then "https://ssl" else "http://www")) + ".google-analytics.com/ga.js"
    firstScript = document.getElementsByTagName("script")[0]
    firstScript.parentNode.insertBefore ga, firstScript

    # If Turbolinks is supported, set up a callback to track pageviews on page:change.
    # If it isn't supported, just track the pageview now.
    if typeof Turbolinks isnt 'undefined' and Turbolinks.supported
      document.addEventListener "page:change", (->
        GoogleAnalytics.trackPageview()
      ), true
    else
      GoogleAnalytics.trackPageview()

  @trackPageview: (url) ->
    unless GoogleAnalytics.isLocalRequest()
      if url
        window._gaq.push ["_trackPageview", url]
      else
        window._gaq.push ["_trackPageview"]
      window._gaq.push ["_trackPageLoadTime"]

  @isLocalRequest: ->
    GoogleAnalytics.documentDomainIncludes "local"

  @documentDomainIncludes: (str) ->
    document.domain.indexOf(str) isnt -1

  @analyticsId: ->
    # your google analytics ID(s) here...
    'UA-xxxxxxxx-x'

GoogleAnalytics.load()

As you can see it adds support for Turbolinks, this is a clean and better way to add Google analytics to your app. Hope it works for you.