Add the option to regenerate the page view ID with each page view event (close #436)

Author: chuwy

package.json

@@ -11,6 +11,7 @@
     "sha1": "git://github.com/pvorb/node-sha1.git#v1.0.0"
   },
   "devDependencies": {
+    "js-base64": "2.1.9",
     "JSON": "1.0.0",
     "grunt": "0.4.5",
     "grunt-browserify": "5.0.0",

src/js/in_queue.js

@@ -46,7 +46,7 @@
 	 *   after the Tracker has been initialized and loaded
 	 ************************************************************/
 
-	object.InQueueManager = function(TrackerConstructor, version, pageViewId, mutSnowplowState, asyncQueue, functionName) {
+	object.InQueueManager = function(TrackerConstructor, version, mutSnowplowState, asyncQueue, functionName) {
 
 		// Page view ID should be shared between all tracker instances
 		var trackerDictionary = {};
@@ -112,7 +112,7 @@
 			argmap = argmap || {};
 
 			if (!trackerDictionary.hasOwnProperty(namespace)) {
-				trackerDictionary[namespace] = new TrackerConstructor(functionName, namespace, version, pageViewId, mutSnowplowState, argmap);
+				trackerDictionary[namespace] = new TrackerConstructor(functionName, namespace, version, mutSnowplowState, argmap);
 				trackerDictionary[namespace].setCollectorUrl(endpoint);
 			} else {
 				helpers.warn('Tracker namespace ' + namespace + ' already exists.');

src/js/snowplow.js

@@ -92,8 +92,6 @@
 			/* Tracker identifier with version */
 			version = 'js-' + '<%= pkg.version %>', // Update banner.js too
 
-			pageViewId = uuid.v4(),
-
 			/* Contains four variables that are shared with tracker.js and must be passed by reference */
 			mutSnowplowState = {
 
@@ -106,7 +104,11 @@
 
 				/* DOM Ready */
 				hasLoaded: false,
-				registeredOnLoadHandlers: []
+				registeredOnLoadHandlers: [],
+
+				/* pageViewId, which can changed by other trackers on page;
+				 * initialized by tracker sent first event */
+				pageViewId: null
 			};
 
 		/************************************************************
@@ -127,7 +129,7 @@
 			// Flush all POST queues
 			lodash.forEach(mutSnowplowState.bufferFlushers, function (flusher) {
 				flusher();
-			})
+			});
 
 			/*
 			 * Delay/pause (blocks UI)
@@ -223,7 +225,7 @@
 			 * @param string distSubdomain The subdomain on your CloudFront collector's distribution
 			 */
 			getTrackerCf: function (distSubdomain) {
-				var t = new tracker.Tracker(functionName, '', version, pageViewId, mutSnowplowState, {});
+				var t = new tracker.Tracker(functionName, '', version, mutSnowplowState, {});
 				t.setCollectorCf(distSubdomain);
 				return t;
 			},
@@ -235,7 +237,7 @@
 			 * @param string rawUrl The collector URL minus protocol and /i
 			 */
 			getTrackerUrl: function (rawUrl) {
-				var t = new tracker.Tracker(functionName, '', version, pageViewId, mutSnowplowState, {});
+				var t = new tracker.Tracker(functionName, '', version, mutSnowplowState, {});
 				t.setCollectorUrl(rawUrl);
 				return t;
 			},
@@ -246,7 +248,7 @@
 			 * @return Tracker
 			 */
 			getAsyncTracker: function () {
-				return new tracker.Tracker(functionName, '', version, pageViewId, mutSnowplowState, {});
+				return new tracker.Tracker(functionName, '', version, mutSnowplowState, {});
 			}
 		};
 
@@ -259,7 +261,7 @@
 		addReadyListener();
 
 		// Now replace initialization array with queue manager object
-		return new queue.InQueueManager(tracker.Tracker, version, pageViewId, mutSnowplowState, asynchronousQueue, functionName);
+		return new queue.InQueueManager(tracker.Tracker, version, mutSnowplowState, asynchronousQueue, functionName);
 	};
 
 }());

src/js/tracker.js

@@ -56,7 +56,6 @@
 	 * @param functionName global function name
 	 * @param namespace The namespace of the tracker object
 	 * @param version The current version of the JavaScript Tracker
-	 * @param pageViewId ID for the current page view, to be attached to all events in the web_page context
 	 * @param mutSnowplowState An object containing hasLoaded, registeredOnLoadHandlers, and expireDateTime
 	 * 	      Passed in by reference in case they are altered by snowplow.js
 	 * @param argmap Optional dictionary of configuration options. Supported fields and their default values:
@@ -82,7 +81,7 @@
 	 * 19. maxPostBytes, 40000
 	 * 20. discoverRootDomain, false
 	 */
-	object.Tracker = function Tracker(functionName, namespace, version, pageViewId, mutSnowplowState, argmap) {
+	object.Tracker = function Tracker(functionName, namespace, version, mutSnowplowState, argmap) {
 
 		/************************************************************
 		 * Private members
@@ -264,16 +263,15 @@
 			commonContexts = [],
 
 			// Enhanced Ecommerce Contexts to be added on every `trackEnhancedEcommerceAction` call
-			enhancedEcommerceContexts = [];
+			enhancedEcommerceContexts = [],
+
+			// Whether pageViewId should be regenerated after each trackPageView. Affect web_page context
+			preservePageViewId = false;
 
 		if (argmap.hasOwnProperty('discoverRootDomain') && argmap.discoverRootDomain) {
 			configCookieDomain = helpers.findRootDomain();
 		}
 
-		if (autoContexts.webPage) {
-			commonContexts.push(getWebPageContext());
-		}
-
 		if (autoContexts.gaCookies) {
 			commonContexts.push(getGaCookiesContext());
 		}
@@ -748,6 +746,10 @@
 		function addCommonContexts(userContexts) {
 			var combinedContexts = commonContexts.concat(userContexts || []);
 
+			if (autoContexts.webPage) {
+				combinedContexts.push(getWebPageContext());
+			}
+
 			// Add PerformanceTiming Context
 			if (autoContexts.performanceTiming) {
 				var performanceTimingContext = getPerformanceTimingContext();
@@ -813,6 +815,27 @@
 			return combinedContexts;
 		}
 
+		/**
+		 * Initialize new `pageViewId` if it shouldn't be preserved.
+		 * Should be called when `trackPageView` is invoked
+		 */
+		function resetPageView() {
+			if (!preservePageViewId || mutSnowplowState.pageViewId == null) {
+				mutSnowplowState.pageViewId = uuid.v4();
+			}
+		}
+
+		/**
+		 * Safe function to get `pageViewId`.
+		 * Generates it if it wasn't initialized by other tracker
+		 */
+		function getPageViewId() {
+			if (mutSnowplowState.pageViewId == null) {
+				mutSnowplowState.pageViewId = uuid.v4();
+			}
+			return mutSnowplowState.pageViewId
+		}
+
 		/**
 		 * Put together a web page context with a unique UUID for the page view
 		 *
@@ -822,7 +845,7 @@
 			return {
 				schema: 'iglu:com.snowplowanalytics.snowplow/web_page/jsonschema/1-0-0',
 				data: {
-					id: pageViewId
+					id: getPageViewId()
 				}
 			};
 		}
@@ -1147,6 +1170,7 @@
 		function logPageView(customTitle, context, contextCallback, tstamp) {
 
 			refreshUrl();
+			resetPageView();
 
 			// So we know what document.title was at the time of trackPageView
 			lastDocumentTitle = documentAlias.title;
@@ -1162,7 +1186,7 @@
 				purify(customReferrer || configReferrerUrl),
 				addCommonContexts(finalizeContexts(context, contextCallback)),
 				tstamp);
-
+			
 			// Send ping (to log that user has stayed on page)
 			var now = new Date();
 			if (configMinimumVisitTime && configHeartBeatTimer && !activityTrackingInstalled) {
@@ -2202,6 +2226,13 @@
 			trackError: function (message, filename, lineno, colno, error, contexts) {
 				var enrichedContexts = addCommonContexts(contexts);
 			    errorManager.trackError(message, filename, lineno, colno, error, enrichedContexts);
+			},
+
+			/**
+			 * Stop regenerating `pageViewId` (available from `web_page` context)
+			 */
+			preservePageViewId: function () {
+				preservePageViewId = true
 			}
 		};
 	};

tests/integration/integration.js

@@ -37,8 +37,10 @@ define([
 	'intern/chai!assert',
 	'intern/dojo/node!lodash',
 	'intern/dojo/node!http',
-	'intern/dojo/node!url'
-], function(registerSuite, assert, lodash, http, url) {
+	'intern/dojo/node!url',
+	"intern/dojo/node!js-base64"
+], function(registerSuite, assert, lodash, http, url, jsBase64) {
+	var decodeBase64 = jsBase64.Base64.fromBase64;
 
 	/**
 	 * Expected amount of request for each browser
@@ -195,9 +197,15 @@ define([
 					// We cannot test more because implementations vary much in old browsers (FF27,IE9)
 					return (event.schema === 'iglu:com.snowplowanalytics.snowplow/application_error/jsonschema/1-0-1') &&
 						(event.data.programmingLanguage === 'JAVASCRIPT') &&
-						(event.data.message != null)
+						(event.data.message != null);
 				}
 			}));
-		}
+		},
+
+
+	    'Check pageViewId is regenerated for each trackPageView': function () {
+		    assert.isTrue(pageViewsHaveDifferentIds());
+	    }
+
 	});
 });

tests/nonfunctional/in_queue.js

@@ -40,7 +40,7 @@ define([
 
 	var output = 0;
 
-	function mockTrackerConstructor (functionName, namespace, version, sessionId, mutSnowplowState, argmap) {
+	function mockTrackerConstructor (functionName, namespace, version, mutSnowplowState, argmap) {
 		var configCollectorUrl,
 			attribute = 10;
 
@@ -68,7 +68,7 @@ define([
 		["increaseAttribute", 5],
 		["setOutputToAttribute"]
 	];
-	asyncQueue = new in_queue.InQueueManager(mockTrackerConstructor, 0, "c7a63a97-ac4a-4d58-8774-33b985701d16", {}, asyncQueue, 'snowplow');
+	asyncQueue = new in_queue.InQueueManager(mockTrackerConstructor, 0, {}, asyncQueue, 'snowplow');
 
 	registerSuite({
 		name: "InQueueManager test",

tests/pages/integration-template.html

@@ -24,7 +24,10 @@
 		window.snowplow('newTracker', 'cf', subdomain + '.ngrok.io', {
 			encodeBase64: true,
 			appId: 'CFe23a',
-			platform: 'mob'
+			platform: 'mob',
+			contexts: {
+				webPage: true
+			}
 		});
 
 		window.snowplow('setUserId', 'Malcolm');
@@ -37,6 +40,9 @@
 			}
 		]);
 
+		// This should have different pageViewId in web_page context
+		window.snowplow('trackPageView');
+
 		window.snowplow('trackStructEvent', 'Mixes', 'Play', 'MRC/fabric-0503-mix', '', '0.0');
 		window.snowplow('trackUnstructEvent', {
 			schema: 'iglu:com.acme_company/viewed_product/jsonschema/5-0-0',