add support for google analytics userId

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 0.3.1
+
+  * [ENHANCEMENT] add support for google analytics userId
+
 # 0.3.0
 
   * [ENHANCEMENT] google analytics cookieDomain renamed to cookie_domain

README.md

@@ -84,6 +84,7 @@ request.env['tracker'] = {
 
 * `:anonymize_ip` -  sets the tracker to remove the last octet from all IP addresses, see https://developers.google.com/analytics/devguides/collection/gajs/methods/gaJSApi_gat?hl=de#_gat._anonymizeIp for details.
 * `:cookie_domain` -  sets the domain name for the GATC cookies. Defaults to `auto`.
+* `:user_id` -  defines a proc to set the [userId](https://developers.google.com/analytics/devguides/collection/analyticsjs/user-id). Ex: `user_id: ->(env) { env['rack.session']['user_id'] }` would return the user_id from the session.
 * `:site_speed_sample_rate` - Defines a new sample set size for Site Speed data collection, see https://developers.google.com/analytics/devguides/collection/gajs/methods/gaJSApiBasicConfiguration?hl=de#_gat.GA_Tracker_._setSiteSpeedSampleRate
 * `:adjusted_bounce_rate_timeouts` - An array of times in seconds that the tracker will use to set timeouts for adjusted bounce rate tracking. See http://analytics.blogspot.ca/2012/07/tracking-adjusted-bounce-rate-in-google.html for details.
 * `:enhanced_link_attribution` - Enables [Enhanced Link Attribution](https://developers.google.com/analytics/devguides/collection/analyticsjs/advanced#enhancedlink).

lib/rack/tracker/google_analytics/google_analytics.rb

@@ -28,6 +28,19 @@ def tracker
     options[:tracker].respond_to?(:call) ? options[:tracker].call(env) : options[:tracker]
   end
 
+  def tracker_options
+    @tracker_options ||= begin
+      tracker_options = {}
+
+      tracker_options[:cookieDomain] = options[:cookie_domain] if options[:cookie_domain]
+
+      user_id = options[:user_id].call(env) if options[:user_id]
+      tracker_options[:userId] = "#{user_id}" if user_id.present?
+
+      tracker_options
+    end
+  end
+
   def render
     Tilt.new( File.join( File.dirname(__FILE__), 'template', 'google_analytics.erb') ).render(self)
   end

lib/rack/tracker/google_analytics/template/google_analytics.erb

@@ -7,7 +7,7 @@
     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', '<%= tracker %>', <%= (options[:cookie_domain] ? {cookieDomain: options[:cookie_domain]} : {}).to_json %>);
+    ga('create', '<%= tracker %>', <%= tracker_options.to_json %>);
   }
 
 <% if options[:enhanced_link_attribution] %>

lib/rack/tracker/version.rb

@@ -1,5 +1,5 @@
 module Rack
   class Tracker
-    VERSION = '0.3.0'
+    VERSION = '0.3.1'
   end
 end

spec/handler/google_analytics_spec.rb

@@ -30,6 +30,34 @@ def env
     end
   end
 
+  describe '#tracker_options' do
+    describe 'with cookie_domain option' do
+      subject { described_class.new(env, { cookie_domain: 'railslabs.com' }) }
+
+      it 'returns hash with cookieDomain' do
+        expect(subject.tracker_options).to eql ({ cookieDomain: 'railslabs.com' })
+      end
+    end
+
+    describe 'with user_id option' do
+      context 'returning a value' do
+        subject { described_class.new(env, { user_id: ->(env){ '123' } }) }
+
+        it 'returns hash with userId' do
+          expect(subject.tracker_options).to eql ({ userId: '123' })
+        end
+      end
+
+      context 'returning nil' do
+        subject { described_class.new(env, { user_id: ->(env){ nil } }) }
+
+        it 'returns hash without userId' do
+          expect(subject.tracker_options).to eql ({ })
+        end
+      end
+    end
+  end
+
   describe "with events" do
     describe "default" do
       def env
@@ -93,6 +121,15 @@ def env
     end
   end
 
+  describe "with user_id tracking" do
+    subject { described_class.new(env, tracker: 'somebody', user_id: ->(env){ '123' } ).render }
+
+    it "will show asyncronous tracker with userId" do
+      expect(subject).to match(%r{ga\('create', 'somebody', {\"userId\":\"123\"}\)})
+      expect(subject).to match(%r{ga\('send', 'pageview'\)})
+    end
+  end
+
   describe "with enhanced_link_attribution" do
     subject { described_class.new(env, tracker: 'happy', enhanced_link_attribution: true).render }