amplitude · djih · Jun 22, 2016 · Jun 22, 2016 · Jun 22, 2016
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,6 +1,7 @@
 ## Unreleased
 
 * Update README with link to our [Google Tag Manager integration demo app](https://github.com/amplitude/GTM-Web-Demo).
+* Fix bug where referrer and UTM params were being captured more than once per session.
 
 ### 3.0.0 (May 27, 2016)
 

diff --git a/amplitude.js b/amplitude.js
@@ -568,6 +568,14 @@ AmplitudeClient.prototype.init = function init(apiKey, opt_userId, opt_config, o
     if (!this._sessionId || !this._lastEventTime || now - this._lastEventTime > this.options.sessionTimeout) {
       this._newSession = true;
       this._sessionId = now;
+
+      // only capture UTM params and referrer if new session
+      if (this.options.includeUtm) {
+        this._initUtmData();
+      }
+      if (this.options.includeReferrer) {
+        this._saveReferrer(this._getReferrer());
+      }
     }
     this._lastEventTime = now;
     _saveCookieData(this);
@@ -594,14 +602,6 @@ AmplitudeClient.prototype.init = function init(apiKey, opt_userId, opt_config, o
 
       this._sendEventsIfReady(); // try sending unsent events
     }
-
-    if (this.options.includeUtm) {
-      this._initUtmData();
-    }
-
-    if (this.options.includeReferrer) {
-      this._saveReferrer(this._getReferrer());
-    }
   } catch (e) {
     utils.log(e);
   } finally {

diff --git a/amplitude.min.js b/amplitude.min.js
diff --git a/documentation/Amplitude.html b/documentation/Amplitude.html
@@ -3137,7 +3137,7 @@ <h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="Amplitude
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Fri May 27 2016 15:00:10 GMT-0700 (PDT)
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Wed Jun 22 2016 14:19:08 GMT-0700 (PDT)
 </footer>
 
 <script> prettyPrint(); </script>

diff --git a/documentation/AmplitudeClient.html b/documentation/AmplitudeClient.html
@@ -2791,7 +2791,7 @@ <h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="Amplitude
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Fri May 27 2016 15:00:10 GMT-0700 (PDT)
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Wed Jun 22 2016 14:19:08 GMT-0700 (PDT)
 </footer>
 
 <script> prettyPrint(); </script>

diff --git a/documentation/Identify.html b/documentation/Identify.html
@@ -1295,7 +1295,7 @@ <h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="Amplitude
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Fri May 27 2016 15:00:10 GMT-0700 (PDT)
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Wed Jun 22 2016 14:19:08 GMT-0700 (PDT)
 </footer>
 
 <script> prettyPrint(); </script>

diff --git a/documentation/Revenue.html b/documentation/Revenue.html
@@ -965,7 +965,7 @@ <h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="Amplitude
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Fri May 27 2016 15:00:10 GMT-0700 (PDT)
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Wed Jun 22 2016 14:19:08 GMT-0700 (PDT)
 </footer>
 
 <script> prettyPrint(); </script>

diff --git a/documentation/amplitude-client.js.html b/documentation/amplitude-client.js.html
@@ -115,6 +115,14 @@ <h1 class="page-title">Source: amplitude-client.js</h1>
     if (!this._sessionId || !this._lastEventTime || now - this._lastEventTime > this.options.sessionTimeout) {
       this._newSession = true;
       this._sessionId = now;
+
+      // only capture UTM params and referrer if new session
+      if (this.options.includeUtm) {
+        this._initUtmData();
+      }
+      if (this.options.includeReferrer) {
+        this._saveReferrer(this._getReferrer());
+      }
     }
     this._lastEventTime = now;
     _saveCookieData(this);
@@ -141,14 +149,6 @@ <h1 class="page-title">Source: amplitude-client.js</h1>
 
       this._sendEventsIfReady(); // try sending unsent events
     }
-
-    if (this.options.includeUtm) {
-      this._initUtmData();
-    }
-
-    if (this.options.includeReferrer) {
-      this._saveReferrer(this._getReferrer());
-    }
   } catch (e) {
     utils.log(e);
   } finally {
@@ -1170,7 +1170,7 @@ <h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="Amplitude
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Fri May 27 2016 15:00:10 GMT-0700 (PDT)
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Wed Jun 22 2016 14:19:08 GMT-0700 (PDT)
 </footer>
 
 <script> prettyPrint(); </script>

diff --git a/documentation/amplitude.js.html b/documentation/amplitude.js.html
@@ -409,7 +409,7 @@ <h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="Amplitude
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Fri May 27 2016 15:00:10 GMT-0700 (PDT)
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Wed Jun 22 2016 14:19:08 GMT-0700 (PDT)
 </footer>
 
 <script> prettyPrint(); </script>

diff --git a/documentation/identify.js.html b/documentation/identify.js.html
@@ -226,7 +226,7 @@ <h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="Amplitude
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Fri May 27 2016 15:00:10 GMT-0700 (PDT)
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Wed Jun 22 2016 14:19:08 GMT-0700 (PDT)
 </footer>
 
 <script> prettyPrint(); </script>

diff --git a/documentation/index.html b/documentation/index.html
@@ -56,7 +56,7 @@ <h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="Amplitude
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Fri May 27 2016 15:00:10 GMT-0700 (PDT)
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Wed Jun 22 2016 14:19:08 GMT-0700 (PDT)
 </footer>
 
 <script> prettyPrint(); </script>

diff --git a/documentation/revenue.js.html b/documentation/revenue.js.html
@@ -200,7 +200,7 @@ <h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="Amplitude
 <br class="clear">
 
 <footer>
-    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Fri May 27 2016 15:00:10 GMT-0700 (PDT)
+    Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.0</a> on Wed Jun 22 2016 14:19:08 GMT-0700 (PDT)
 </footer>
 
 <script> prettyPrint(); </script>

diff --git a/src/amplitude-client.js b/src/amplitude-client.js
@@ -87,6 +87,14 @@ AmplitudeClient.prototype.init = function init(apiKey, opt_userId, opt_config, o
     if (!this._sessionId || !this._lastEventTime || now - this._lastEventTime > this.options.sessionTimeout) {
       this._newSession = true;
       this._sessionId = now;
+
+      // only capture UTM params and referrer if new session
+      if (this.options.includeUtm) {
+        this._initUtmData();
+      }
+      if (this.options.includeReferrer) {
+        this._saveReferrer(this._getReferrer());
+      }
     }
     this._lastEventTime = now;
     _saveCookieData(this);
@@ -113,14 +121,6 @@ AmplitudeClient.prototype.init = function init(apiKey, opt_userId, opt_config, o
 
       this._sendEventsIfReady(); // try sending unsent events
     }
-
-    if (this.options.includeUtm) {
-      this._initUtmData();
-    }
-
-    if (this.options.includeReferrer) {
-      this._saveReferrer(this._getReferrer());
-    }
   } catch (e) {
     utils.log(e);
   } finally {

diff --git a/test/amplitude-client.js b/test/amplitude-client.js
@@ -2054,17 +2054,21 @@ describe('setVersionName', function() {
   });
 
   describe('gatherUtm', function() {
+    var clock;
     beforeEach(function() {
+      clock = sinon.useFakeTimers(100);
       amplitude.init(apiKey);
     });
 
     afterEach(function() {
       reset();
+      clock.restore();
     });
 
     it('should not send utm data when the includeUtm flag is false', function() {
-      cookie.set('__utmz', '133232535.1424926227.1.1.utmcct=top&utmccn=new');
       reset();
+      cookie.set('__utmz', '133232535.1424926227.1.1.utmcct=top&utmccn=new');
+      clock.tick(30 * 60 * 1000 + 1);
       amplitude.init(apiKey, undefined, {});
 
       amplitude.setUserProperties({user_prop: true});
@@ -2078,8 +2082,9 @@ describe('setVersionName', function() {
     });
 
     it('should send utm data via identify when the includeUtm flag is true', function() {
-      cookie.set('__utmz', '133232535.1424926227.1.1.utmcct=top&utmccn=new');
       reset();
+      cookie.set('__utmz', '133232535.1424926227.1.1.utmcct=top&utmccn=new');
+      clock.tick(30 * 60 * 1000 + 1);
       amplitude.init(apiKey, undefined, {includeUtm: true, batchEvents: true, eventUploadThreshold: 2});
 
       amplitude.logEvent('UTM Test Event', {});
@@ -2103,9 +2108,10 @@ describe('setVersionName', function() {
     });
 
     it('should parse utm params', function() {
+      reset();
       cookie.set('__utmz', '133232535.1424926227.1.1.utmcct=top&utmccn=new');
-
       var utmParams = '?utm_source=amplitude&utm_medium=email&utm_term=terms';
+      clock.tick(30 * 60 * 1000 + 1);
       amplitude._initUtmData(utmParams);
 
       var expectedProperties = {
@@ -2154,6 +2160,7 @@ describe('setVersionName', function() {
 
       cookie.set('__utmz', '133232535.1424926227.1.1.utmcct=top&utmccn=new');
       var utmParams = '?utm_source=amplitude&utm_medium=email&utm_term=terms';
+      clock.tick(30 * 60 * 1000 + 1);
       amplitude._initUtmData(utmParams);
 
       assert.lengthOf(server.requests, 1);
@@ -2175,20 +2182,57 @@ describe('setVersionName', function() {
       // should not override any existing utm properties values in session storage
       assert.equal(sessionStorage.getItem('amplitude_utm_properties'), JSON.stringify(existingProperties));
     });
+
+    it('should only send utm data once per session', function() {
+      reset();
+      cookie.set('__utmz', '133232535.1424926227.1.1.utmcct=top&utmccn=new');
+      amplitude.init(apiKey, undefined, {includeUtm: true});
+
+      // still same session, should not send any identify events
+      assert.lengthOf(server.requests, 0);
+      assert.lengthOf(amplitude._unsentEvents, 0);
+      assert.lengthOf(amplitude._unsentIdentifys, 0);
+
+      // advance clock to force new session
+      clock.tick(30 * 60 * 1000 + 1);
+      amplitude.init(apiKey, undefined, {includeUtm: true, batchEvents: true, eventUploadThreshold: 2});
+      amplitude.logEvent('UTM Test Event', {});
+
+      assert.lengthOf(server.requests, 1);
+      var events = JSON.parse(querystring.parse(server.requests[0].requestBody).e);
+      assert.equal(events[0].event_type, '$identify');
+      assert.deepEqual(events[0].user_properties, {
+        '$setOnce': {
+          initial_utm_campaign: 'new',
+          initial_utm_content: 'top'
+        },
+        '$set': {
+          utm_campaign: 'new',
+          utm_content: 'top'
+        }
+      });
+
+      assert.equal(events[1].event_type, 'UTM Test Event');
+      assert.deepEqual(events[1].user_properties, {});
+    });
   });
 
   describe('gatherReferrer', function() {
+    var clock;
     beforeEach(function() {
+      clock = sinon.useFakeTimers(100);
       amplitude.init(apiKey);
       sinon.stub(amplitude, '_getReferrer').returns('https://amplitude.com/contact');
     });
 
     afterEach(function() {
       amplitude._getReferrer.restore();
+      clock.restore();
       reset();
     });
 
     it('should not send referrer data when the includeReferrer flag is false', function() {
+      clock.tick(30 * 60 * 1000 + 1);
       amplitude.init(apiKey, undefined, {});
 
       amplitude.setUserProperties({user_prop: true});
@@ -2200,6 +2244,7 @@ describe('setVersionName', function() {
 
     it('should only send referrer via identify call when the includeReferrer flag is true', function() {
       reset();
+      clock.tick(30 * 60 * 1000 + 1);
       amplitude.init(apiKey, undefined, {includeReferrer: true, batchEvents: true, eventUploadThreshold: 2});
       amplitude.logEvent('Referrer Test Event', {});
       assert.lengthOf(server.requests, 1);
@@ -2231,6 +2276,7 @@ describe('setVersionName', function() {
 
     it('should not set referrer if referrer data already in session storage', function() {
       reset();
+      clock.tick(30 * 60 * 1000 + 1);
       sessionStorage.setItem('amplitude_referrer', 'https://www.google.com/search?');
       amplitude.init(apiKey, undefined, {includeReferrer: true, batchEvents: true, eventUploadThreshold: 2});
       amplitude.logEvent('Referrer Test Event', {});
@@ -2254,6 +2300,7 @@ describe('setVersionName', function() {
 
     it('should not override any existing initial referrer values in session storage', function() {
       reset();
+      clock.tick(30 * 60 * 1000 + 1);
       sessionStorage.setItem('amplitude_referrer', 'https://www.google.com/search?');
       amplitude.init(apiKey, undefined, {includeReferrer: true, batchEvents: true, eventUploadThreshold: 3});
       amplitude._saveReferrer('https://facebook.com/contact');
@@ -2327,6 +2374,46 @@ describe('setVersionName', function() {
       // existing value persists
       assert.equal(sessionStorage.getItem('amplitude_referrer_new_app'), 'https://www.google.com/search?');
     });
+
+    it('should only send referrer once per session', function() {
+      reset();
+      amplitude.init(apiKey, undefined, {includeReferrer: true});
+
+      // still same session, no referrer sent
+      assert.lengthOf(server.requests, 0);
+      assert.lengthOf(amplitude._unsentEvents, 0);
+      assert.lengthOf(amplitude._unsentIdentifys, 0);
+
+      // advance the clock to force a new session
+      clock.tick(30 * 60 * 1000 + 1);
+      amplitude.init(apiKey, undefined, {includeReferrer: true, batchEvents: true, eventUploadThreshold: 2});
+      amplitude.logEvent('Referrer Test Event', {});
+      assert.lengthOf(server.requests, 1);
+      var events = JSON.parse(querystring.parse(server.requests[0].requestBody).e);
+      assert.lengthOf(events, 2);
+
+      var expected = {
+        'referrer': 'https://amplitude.com/contact',
+        'referring_domain': 'amplitude.com'
+      };
+
+      // first event should be identify with initial_referrer and referrer
+      assert.equal(events[0].event_type, '$identify');
+      assert.deepEqual(events[0].user_properties, {
+        '$set': expected,
+        '$setOnce': {
+          'initial_referrer': 'https://amplitude.com/contact',
+          'initial_referring_domain': 'amplitude.com'
+        }
+      });
+
+      // second event should be the test event with no referrer information
+      assert.equal(events[1].event_type, 'Referrer Test Event');
+      assert.deepEqual(events[1].user_properties, {});
+
+      // referrer should be propagated to session storage
+      assert.equal(sessionStorage.getItem('amplitude_referrer'), JSON.stringify(expected));
+    });
   });
 
   describe('logRevenue', function() {
@@ -2502,4 +2589,4 @@ describe('setVersionName', function() {
       assert.equal(amplitude2.getSessionId(), amplitude2._sessionId);
     });
   });
-});
+});