Support cross domain event tracking

javascripts/govuk/analytics/google-analytics-universal-tracker.js

@@ -74,6 +74,7 @@
   GoogleAnalyticsUniversalTracker.prototype.trackEvent = function (category, action, options) {
     options = options || {}
     var value
+    var trackerName = ''
     var evt = {
       hitType: 'event',
       eventCategory: category,
@@ -97,6 +98,12 @@
       delete options.value
     }
 
+    // trackerName is optional
+    if (typeof options.trackerName === 'string') {
+      trackerName = options.trackerName + '.'
+      delete options.trackerName
+    }
+
     // Prevents an event from affecting bounce rate
     // https://developers.google.com/analytics/devguides/collection/analyticsjs/events#implementation
     if (options.nonInteraction) {
@@ -107,7 +114,7 @@
       $.extend(evt, options)
     }
 
-    sendToGa('send', evt)
+    sendToGa(trackerName + 'send', evt)
   }
 
   /*
@@ -132,11 +139,13 @@
 
   /*
    https://developers.google.com/analytics/devguides/collection/analyticsjs/cross-domain
-   trackerId - the UA account code to track the domain against
-   name      - name for the tracker
-   domain    - the domain to track
+   trackerId    - the UA account code to track the domain against
+   name         - name for the tracker
+   domain       - the domain to track
+   sendPageView - optional argument which controls the legacy behaviour of sending a pageview
+                  on creation of the linked domain.
   */
-  GoogleAnalyticsUniversalTracker.prototype.addLinkedTrackerDomain = function (trackerId, name, domain) {
+  GoogleAnalyticsUniversalTracker.prototype.addLinkedTrackerDomain = function (trackerId, name, domain, sendPageView) {
     sendToGa('create',
              trackerId,
              'auto',
@@ -151,7 +160,10 @@
 
     sendToGa(name + '.set', 'anonymizeIp', true)
     sendToGa(name + '.set', 'displayFeaturesTask', null)
-    sendToGa(name + '.send', 'pageview')
+
+    if (typeof sendPageView === 'undefined' || sendPageView === true) {
+      sendToGa(name + '.send', 'pageview')
+    }
   }
 
   // https://developers.google.com/analytics/devguides/collection/analyticsjs/custom-dims-mets

spec/unit/analytics/google-analytics-universal-tracker.spec.js

@@ -114,6 +114,13 @@ describe('GOVUK.GoogleAnalyticsUniversalTracker', function () {
       )
     })
 
+    it('the option trackerName overrides the default tracker', function () {
+      universal.trackEvent('category', 'action', {trackerName: 'testTracker'})
+      expect(window.ga.calls.mostRecent().args).toEqual(
+        ['testTracker.send', {hitType: 'event', eventCategory: 'category', eventAction: 'action'}]
+      )
+    })
+
     it('only sends values if they are parseable as numbers', function () {
       universal.trackEvent('category', 'action', {label: 'label', value: '10'})
       expect(eventObjectFromSpy()['eventValue']).toEqual(10)
@@ -184,4 +191,27 @@ describe('GOVUK.GoogleAnalyticsUniversalTracker', function () {
       expect(window.ga.calls.mostRecent().args[2]).toContain('address=[email]')
     })
   })
+
+  describe('adding a linked tracker', function () {
+    var callIndex
+
+    beforeEach(function () {
+      callIndex = window.ga.calls.count()
+      universal.addLinkedTrackerDomain('UA-123456', 'testTracker', 'some.service.gov.uk')
+    })
+    it('creates a tracker for the ID', function () {
+      expect(window.ga.calls.argsFor(callIndex)).toEqual(['create', 'UA-123456', 'auto', Object({ name: 'testTracker' })])
+    })
+    it('requires and configures the linker plugin', function () {
+      expect(window.ga.calls.argsFor(callIndex + 1)).toEqual(['require', 'linker'])
+      expect(window.ga.calls.argsFor(callIndex + 2)).toEqual(['testTracker.require', 'linker'])
+    })
+    it('sends a pageview', function () {
+      expect(window.ga.calls.mostRecent().args).toEqual(['testTracker.send', 'pageview'])
+    })
+    it('can omit sending a pageview', function () {
+      universal.addLinkedTrackerDomain('UA-123456', 'testTracker', 'some.service.gov.uk', false)
+      expect(window.ga.calls.mostRecent().args).not.toEqual(['testTracker.send', 'pageview'])
+    })
+  })
 })