comparison core.js @ 841:71fd099e9fd2

Started some user guide

+/**
+ * core.js
+ * 
+ * Main script to run, calls all other core functions and manages loading/store to backend.
+ * Also contains all global variables.
+ */
+
+/* create the web audio API context and store in audioContext*/
+var audioContext; // Hold the browser web audio API
+var projectXML; // Hold the parsed setup XML
+var specification;
+var interfaceContext;
+var popup; // Hold the interfacePopup object
+var testState;
+var currentTrackOrder = []; // Hold the current XML tracks in their (randomised) order
+var audioEngineContext; // The custome AudioEngine object
+var projectReturn; // Hold the URL for the return
+
+
+// Add a prototype to the bufferSourceNode to reference to the audioObject holding it
+AudioBufferSourceNode.prototype.owner = undefined;
+
+window.onload = function() {
+	// Function called once the browser has loaded all files.
+	// This should perform any initial commands such as structure / loading documents
+	
+	// Create a web audio API context
+	// Fixed for cross-browser support
+	var AudioContext = window.AudioContext || window.webkitAudioContext;
+	audioContext = new AudioContext;
+	
+	// Create test state
+	testState = new stateMachine();
+	
+	// Create the audio engine object
+	audioEngineContext = new AudioEngine();
+	
+	// Create the popup interface object
+	popup = new interfacePopup();
+	
+	// Create the specification object
+	specification = new Specification();
+	
+	// Create the interface object
+	interfaceContext = new Interface(specification);
+};
+
+function interfacePopup() {
+	// Creates an object to manage the popup
+	this.popup = null;
+	this.popupContent = null;
+	this.buttonProceed = null;
+	this.buttonPrevious = null;
+	this.popupOptions = null;
+	this.currentIndex = null;
+	this.responses = null;
+	
+	this.createPopup = function(){
+		// Create popup window interface
+		var insertPoint = document.getElementById("topLevelBody");
+		var blank = document.createElement('div');
+		blank.className = 'testHalt';
+		
+		this.popup = document.createElement('div');
+		this.popup.id = 'popupHolder';
+		this.popup.className = 'popupHolder';
+		this.popup.style.position = 'absolute';
+		this.popup.style.left = (window.innerWidth/2)-250 + 'px';
+		this.popup.style.top = (window.innerHeight/2)-125 + 'px';
+		
+		this.popupContent = document.createElement('div');
+		this.popupContent.id = 'popupContent';
+		this.popupContent.style.marginTop = '25px';
+		this.popupContent.align = 'center';
+		this.popup.appendChild(this.popupContent);
+		
+		this.buttonProceed = document.createElement('button');
+		this.buttonProceed.className = 'popupButton';
+		this.buttonProceed.style.left = '440px';
+		this.buttonProceed.style.top = '215px';
+		this.buttonProceed.innerHTML = 'Next';
+		this.buttonProceed.onclick = function(){popup.proceedClicked();};
+		
+		this.buttonPrevious = document.createElement('button');
+		this.buttonPrevious.className = 'popupButton';
+		this.buttonPrevious.style.left = '10px';
+		this.buttonPrevious.style.top = '215px';
+		this.buttonPrevious.innerHTML = 'Back';
+		this.buttonPrevious.onclick = function(){popup.previousClick();};
+		
+		this.popup.style.zIndex = -1;
+		this.popup.style.visibility = 'hidden';
+		blank.style.zIndex = -2;
+		blank.style.visibility = 'hidden';
+		insertPoint.appendChild(this.popup);
+		insertPoint.appendChild(blank);
+	};
+	
+	this.showPopup = function(){
+		if (this.popup == null) {
+			this.createPopup();
+		}
+		this.popup.style.zIndex = 3;
+		this.popup.style.visibility = 'visible';
+		var blank = document.getElementsByClassName('testHalt')[0];
+		blank.style.zIndex = 2;
+		blank.style.visibility = 'visible';
+		$(window).keypress(function(e){
+			if (e.keyCode == 13 && popup.popup.style.visibility == 'visible')
+			{
+				// Enter key pressed
+				var textarea = $(popup.popupContent).find('textarea');
+				if (textarea.length != 0)
+				{
+					if (textarea[0] == document.activeElement)
+					{return;}
+				}
+				popup.buttonProceed.onclick();
+			}
+		});
+	};
+	
+	this.hidePopup = function(){
+		this.popup.style.zIndex = -1;
+		this.popup.style.visibility = 'hidden';
+		var blank = document.getElementsByClassName('testHalt')[0];
+		blank.style.zIndex = -2;
+		blank.style.visibility = 'hidden';
+	};
+	
+	this.postNode = function() {
+		// This will take the node from the popupOptions and display it
+		var node = this.popupOptions[this.currentIndex];
+		this.popupContent.innerHTML = null;
+		if (node.type == 'statement') {
+			var span = document.createElement('span');
+			span.textContent = node.statement;
+			this.popupContent.appendChild(span);
+		} else if (node.type == 'question') {
+			var span = document.createElement('span');
+			span.textContent = node.question;
+			var textArea = document.createElement('textarea');
+			switch (node.boxsize) {
+			case 'small':
+				textArea.cols = "20";
+				textArea.rows = "1";
+				break;
+			case 'normal':
+				textArea.cols = "30";
+				textArea.rows = "2";
+				break;
+			case 'large':
+				textArea.cols = "40";
+				textArea.rows = "5";
+				break;
+			case 'huge':
+				textArea.cols = "50";
+				textArea.rows = "10";
+				break;
+			}
+			var br = document.createElement('br');
+			this.popupContent.appendChild(span);
+			this.popupContent.appendChild(br);
+			this.popupContent.appendChild(textArea);
+			this.popupContent.childNodes[2].focus();
+		} else if (node.type == 'checkbox') {
+			var span = document.createElement('span');
+			span.textContent = node.statement;
+			this.popupContent.appendChild(span);
+			var optHold = document.createElement('div');
+			optHold.id = 'option-holder';
+			optHold.align = 'left';
+			for (var i=0; i<node.options.length; i++) {
+				var option = node.options[i];
+				var input = document.createElement('input');
+				input.id = option.id;
+				input.type = 'checkbox';
+				var span = document.createElement('span');
+				span.textContent = option.text;
+				var hold = document.createElement('div');
+				hold.setAttribute('name','option');
+				hold.style.float = 'left';
+				hold.style.padding = '4px';
+				hold.appendChild(input);
+				hold.appendChild(span);
+				optHold.appendChild(hold);
+			}
+			this.popupContent.appendChild(optHold);
+		} else if (node.type == 'radio') {
+			var span = document.createElement('span');
+			span.textContent = node.statement;
+			this.popupContent.appendChild(span);
+			var optHold = document.createElement('div');
+			optHold.id = 'option-holder';
+			optHold.align = 'none';
+			optHold.style.float = 'left';
+			optHold.style.width = "100%";
+			for (var i=0; i<node.options.length; i++) {
+				var option = node.options[i];
+				var input = document.createElement('input');
+				input.id = option.name;
+				input.type = 'radio';
+				input.name = node.id;
+				var span = document.createElement('span');
+				span.textContent = option.text;
+				var hold = document.createElement('div');
+				hold.setAttribute('name','option');
+				hold.style.padding = '4px';
+				hold.appendChild(input);
+				hold.appendChild(span);
+				optHold.appendChild(hold);
+			}
+			this.popupContent.appendChild(optHold);
+		} else if (node.type == 'number') {
+			var span = document.createElement('span');
+			span.textContent = node.statement;
+			this.popupContent.appendChild(span);
+			this.popupContent.appendChild(document.createElement('br'));
+			var input = document.createElement('input');
+			input.type = 'textarea';
+			if (node.min != null) {input.min = node.min;}
+			if (node.max != null) {input.max = node.max;}
+			if (node.step != null) {input.step = node.step;}
+			this.popupContent.appendChild(input);
+		}
+		this.popupContent.appendChild(this.buttonProceed);
+		if(this.currentIndex+1 == this.popupOptions.length) {
+			if (this.responses.nodeName == "PRETEST") {
+				this.buttonProceed.textContent = 'Start';
+			} else {
+				this.buttonProceed.textContent = 'Submit';
+			}
+		} else {
+			this.buttonProceed.textContent = 'Next';
+		}
+		if(this.currentIndex > 0)
+			this.popupContent.appendChild(this.buttonPrevious);
+	};
+	
+	this.initState = function(node) {
+		//Call this with your preTest and postTest nodes when needed to
+		// initialise the popup procedure.
+		this.popupOptions = node.options;
+		if (this.popupOptions.length > 0) {
+			if (node.type == 'pretest') {
+				this.responses = document.createElement('PreTest');
+			} else if (node.type == 'posttest') {
+				this.responses = document.createElement('PostTest');
+			} else {
+				console.log ('WARNING - popup node neither pre or post!');
+				this.responses = document.createElement('responses');
+			}
+			this.currentIndex = 0;
+			this.showPopup();
+			this.postNode();
+		} else {
+			advanceState();
+		}
+	};
+	
+	this.proceedClicked = function() {
+		// Each time the popup button is clicked!
+		var node = this.popupOptions[this.currentIndex];
+		if (node.type == 'question') {
+			// Must extract the question data
+			var textArea = $(popup.popupContent).find('textarea')[0];
+			if (node.mandatory == true && textArea.value.length == 0) {
+				alert('This question is mandatory');
+				return;
+			} else {
+				// Save the text content
+				var hold = document.createElement('comment');
+				hold.id = node.id;
+				hold.innerHTML = textArea.value;
+				console.log("Question: "+ node.question);
+				console.log("Question Response: "+ textArea.value);
+				this.responses.appendChild(hold);
+			}
+		} else if (node.type == 'checkbox') {
+			// Must extract checkbox data
+			var optHold = document.getElementById('option-holder');
+			var hold = document.createElement('checkbox');
+			console.log("Checkbox: "+ node.statement);
+			hold.id = node.id;
+			for (var i=0; i<optHold.childElementCount; i++) {
+				var input = optHold.childNodes[i].getElementsByTagName('input')[0];
+				var statement = optHold.childNodes[i].getElementsByTagName('span')[0];
+				var response = document.createElement('option');
+				response.setAttribute('name',input.id);
+				response.textContent = input.checked;
+				hold.appendChild(response);
+				console.log(input.id +': '+ input.checked);
+			}
+			this.responses.appendChild(hold);
+		} else if (node.type == "radio") {
+			var optHold = document.getElementById('option-holder');
+			var hold = document.createElement('radio');
+			var responseID = null;
+			var i=0;
+			while(responseID == null) {
+				var input = optHold.childNodes[i].getElementsByTagName('input')[0];
+				if (input.checked == true) {
+					responseID = i;
+				}
+				i++;
+			}
+			hold.id = node.id;
+			hold.setAttribute('name',node.options[responseID].name);
+			hold.textContent = node.options[responseID].text;
+			this.responses.appendChild(hold);
+		} else if (node.type == "number") {
+			var input = this.popupContent.getElementsByTagName('input')[0];
+			if (node.mandatory == true && input.value.length == 0) {
+				alert('This question is mandatory. Please enter a number');
+				return;
+			}
+			var enteredNumber = Number(input.value);
+			if (isNaN(enteredNumber)) {
+				alert('Please enter a valid number');
+				return;
+			}
+			if (enteredNumber < node.min && node.min != null) {
+				alert('Number is below the minimum value of '+node.min);
+				return;
+			}
+			if (enteredNumber > node.max && node.max != null) {
+				alert('Number is above the maximum value of '+node.max);
+				return;
+			}
+			var hold = document.createElement('number');
+			hold.id = node.id;
+			hold.textContent = input.value;
+			this.responses.appendChild(hold);
+		}
+		this.currentIndex++;
+		if (this.currentIndex < this.popupOptions.length) {
+			this.postNode();
+		} else {
+			// Reached the end of the popupOptions
+			this.hidePopup();
+			if (this.responses.nodeName == testState.stateResults[testState.stateIndex].nodeName) {
+				testState.stateResults[testState.stateIndex] = this.responses;
+			} else {
+				testState.stateResults[testState.stateIndex].appendChild(this.responses);
+			}
+			advanceState();
+		}
+	};
+	
+	this.previousClick = function() {
+		// Triggered when the 'Back' button is clicked in the survey
+		if (this.currentIndex > 0) {
+			this.currentIndex--;
+			var node = this.popupOptions[this.currentIndex];
+			if (node.type != 'statement') {
+				var prevResp = this.responses.childNodes[this.responses.childElementCount-1];
+				this.responses.removeChild(prevResp);
+			}
+			this.postNode();
+			if (node.type == 'question') {
+				this.popupContent.getElementsByTagName('textarea')[0].value = prevResp.textContent;
+			} else if (node.type == 'checkbox') {
+				var options = this.popupContent.getElementsByTagName('input');
+				var savedOptions = prevResp.getElementsByTagName('option');
+				for (var i=0; i<options.length; i++) {
+					var id = options[i].id;
+					for (var j=0; j<savedOptions.length; j++) {
+						if (savedOptions[j].getAttribute('name') == id) {
+							if (savedOptions[j].textContent == 'true') {options[i].checked = true;}
+							else {options[i].checked = false;}
+							break;
+						}
+					}
+				}
+			} else if (node.type == 'number') {
+				this.popupContent.getElementsByTagName('input')[0].value = prevResp.textContent;
+			} else if (node.type == 'radio') {
+				var options = this.popupContent.getElementsByTagName('input');
+				var name = prevResp.getAttribute('name');
+				for (var i=0; i<options.length; i++) {
+					if (options[i].id == name) {
+						options[i].checked = true;
+						break;
+					}
+				}
+			}
+		}
+	};
+}
+
+function advanceState()
+{
+	// Just for complete clarity
+	testState.advanceState();
+}
+
+function stateMachine()
+{
+	// Object prototype for tracking and managing the test state
+	this.stateMap = [];
+	this.stateIndex = null;
+	this.currentStateMap = [];
+	this.currentIndex = null;
+	this.currentTestId = 0;
+	this.stateResults = [];
+	this.timerCallBackHolders = null;
+	this.initialise = function(){
+		if (this.stateMap.length > 0) {
+			if(this.stateIndex != null) {
+				console.log('NOTE - State already initialise');
+			}
+			this.stateIndex = -1;
+			var that = this;
+			var aH_pId = 0;
+			for (var id=0; id<this.stateMap.length; id++){
+				var name = this.stateMap[id].type;
+				var obj = document.createElement(name);
+				if (name == 'audioHolder') {
+					obj.id = this.stateMap[id].id;
+					obj.setAttribute('presentedid',aH_pId);
+					aH_pId+=1;
+				}
+				this.stateResults.push(obj);
+			}
+		} else {
+			console.log('FATAL - StateMap not correctly constructed. EMPTY_STATE_MAP');
+		}
+	};
+	this.advanceState = function(){
+		if (this.stateIndex == null) {
+			this.initialise();
+		}
+		if (this.stateIndex == -1) {
+			console.log('Starting test...');
+		}
+		if (this.currentIndex == null){
+			if (this.currentStateMap.type == "audioHolder") {
+				// Save current page
+				this.testPageCompleted(this.stateResults[this.stateIndex],this.currentStateMap,this.currentTestId);
+				this.currentTestId++;
+			}
+			this.stateIndex++;
+			if (this.stateIndex >= this.stateMap.length) {
+				console.log('Test Completed');
+				createProjectSave(specification.projectReturn);
+			} else {
+				this.currentStateMap = this.stateMap[this.stateIndex];
+				if (this.currentStateMap.type == "audioHolder") {
+					console.log('Loading test page');
+					loadTest(this.currentStateMap);
+					this.initialiseInnerState(this.currentStateMap);
+				} else if (this.currentStateMap.type == "pretest" || this.currentStateMap.type == "posttest") {
+					if (this.currentStateMap.options.length >= 1) {
+						popup.initState(this.currentStateMap);
+					} else {
+						this.advanceState();
+					}
+				} else {
+					this.advanceState();
+				}
+			}
+		} else {
+			this.advanceInnerState();
+		}
+	};
+	
+	this.testPageCompleted = function(store, testXML, testId) {
+		// Function called each time a test page has been completed
+		// Can be used to over-rule default behaviour
+		
+		pageXMLSave(store, testXML);
+	};
+	
+	this.initialiseInnerState = function(node) {
+		// Parses the received testXML for pre and post test options
+		this.currentStateMap = [];
+		var preTest = node.preTest;
+		var postTest = node.postTest;
+		if (preTest == undefined) {preTest = document.createElement("preTest");}
+		if (postTest == undefined){postTest= document.createElement("postTest");}
+		this.currentStateMap.push(preTest);
+		this.currentStateMap.push(node);
+		this.currentStateMap.push(postTest);
+		this.currentIndex = -1;
+		this.advanceInnerState();
+	};
+	
+	this.advanceInnerState = function() {
+		this.currentIndex++;
+		if (this.currentIndex >= this.currentStateMap.length) {
+			this.currentIndex = null;
+			this.currentStateMap = this.stateMap[this.stateIndex];
+			this.advanceState();
+		} else {
+			if (this.currentStateMap[this.currentIndex].type == "audioHolder") {
+				console.log("Loading test page"+this.currentTestId);
+			} else if (this.currentStateMap[this.currentIndex].type == "pretest") {
+				popup.initState(this.currentStateMap[this.currentIndex]);
+			} else if (this.currentStateMap[this.currentIndex].type == "posttest") {
+				popup.initState(this.currentStateMap[this.currentIndex]);
+			} else {
+				this.advanceInnerState();
+			}
+		}
+	};
+	
+	this.previousState = function(){};
+}
+
+function testEnded(testId)
+{
+	pageXMLSave(testId);
+	if (testXMLSetups.length-1 > testId)
+	{
+		// Yes we have another test to perform
+		testId = (Number(testId)+1);
+		currentState = 'testRun-'+testId;
+		loadTest(testId);
+	} else {
+		console.log('Testing Completed!');
+		currentState = 'postTest';
+		// Check for any post tests
+		var xmlSetup = projectXML.find('setup');
+		var postTest = xmlSetup.find('PostTest')[0];
+		popup.initState(postTest);
+	}
+}
+
+function loadProjectSpec(url) {
+	// Load the project document from the given URL, decode the XML and instruct audioEngine to get audio data
+	// If url is null, request client to upload project XML document
+	var r = new XMLHttpRequest();
+	r.open('GET',url,true);
+	r.onload = function() {
+		loadProjectSpecCallback(r.response);
+	};
+	r.send();
+};
+
+function loadProjectSpecCallback(response) {
+	// Function called after asynchronous download of XML project specification
+	//var decode = $.parseXML(response);
+	//projectXML = $(decode);
+	
+	var parse = new DOMParser();
+	projectXML = parse.parseFromString(response,'text/xml');
+	
+	// Build the specification
+	specification.decode();
+	
+	testState.stateMap.push(specification.preTest);
+	 
+	// New check if we need to randomise the test order
+	if (specification.randomiseOrder)
+	{
+ 		specification.audioHolders = randomiseOrder(specification.audioHolders);
+ 		for (var i=0; i<specification.audioHolders.length; i++)
+ 		{
+ 			specification.audioHolders[i].presentedId = i;
+ 		}
+	}
+	
+	$(specification.audioHolders).each(function(index,elem){
+		testState.stateMap.push(elem);
+	});
+	 
+	 testState.stateMap.push(specification.postTest);
+	 
+	// Obtain the metrics enabled
+	$(specification.metrics).each(function(index,node){
+		var enabled = node.textContent;
+		switch(node.enabled)
+		{
+		case 'testTimer':
+			sessionMetrics.prototype.enableTestTimer = true;
+			break;
+		case 'elementTimer':
+			sessionMetrics.prototype.enableElementTimer = true;
+			break;
+		case 'elementTracker':
+			sessionMetrics.prototype.enableElementTracker = true;
+			break;
+		case 'elementListenTracker':
+			sessionMetrics.prototype.enableElementListenTracker = true;
+			break;
+		case 'elementInitialPosition':
+			sessionMetrics.prototype.enableElementInitialPosition = true;
+			break;
+		case 'elementFlagListenedTo':
+			sessionMetrics.prototype.enableFlagListenedTo = true;
+			break;
+		case 'elementFlagMoved':
+			sessionMetrics.prototype.enableFlagMoved = true;
+			break;
+		case 'elementFlagComments':
+			sessionMetrics.prototype.enableFlagComments = true;
+			break;
+		}
+	});
+	
+	
+	
+	// Detect the interface to use and load the relevant javascripts.
+	var interfaceJS = document.createElement('script');
+	interfaceJS.setAttribute("type","text/javascript");
+	if (specification.interfaceType == 'APE') {
+		interfaceJS.setAttribute("src","ape.js");
+		
+		// APE comes with a css file
+		var css = document.createElement('link');
+		css.rel = 'stylesheet';
+		css.type = 'text/css';
+		css.href = 'ape.css';
+		
+		document.getElementsByTagName("head")[0].appendChild(css);
+	} else if (specification.interfaceType == "MUSHRA")
+	{
+		interfaceJS.setAttribute("src","mushra.js");
+		
+		// MUSHRA comes with a css file
+		var css = document.createElement('link');
+		css.rel = 'stylesheet';
+		css.type = 'text/css';
+		css.href = 'mushra.css';
+		
+		document.getElementsByTagName("head")[0].appendChild(css);
+	}
+	document.getElementsByTagName("head")[0].appendChild(interfaceJS);
+	
+	// Define window callbacks for interface
+	window.onresize = function(event){resizeWindow(event);};
+}
+
+function createProjectSave(destURL) {
+	// Save the data from interface into XML and send to destURL
+	// If destURL is null then download XML in client
+	// Now time to render file locally
+	var xmlDoc = interfaceXMLSave();
+	var parent = document.createElement("div");
+	parent.appendChild(xmlDoc);
+	var file = [parent.innerHTML];
+	if (destURL == "null" || destURL == undefined) {
+		var bb = new Blob(file,{type : 'application/xml'});
+		var dnlk = window.URL.createObjectURL(bb);
+		var a = document.createElement("a");
+		a.hidden = '';
+		a.href = dnlk;
+		a.download = "save.xml";
+		a.textContent = "Save File";
+		
+		popup.showPopup();
+		popup.popupContent.innerHTML = null;
+		popup.popupContent.appendChild(a);
+	} else {
+		var xmlhttp = new XMLHttpRequest;
+		xmlhttp.open("POST",destURL,true);
+		xmlhttp.setRequestHeader('Content-Type', 'text/xml');
+		xmlhttp.onerror = function(){
+			console.log('Error saving file to server! Presenting download locally');
+			createProjectSave(null);
+		};
+		xmlhttp.onreadystatechange  = function() {
+			console.log(xmlhttp.status);
+			if (xmlhttp.status != 200 && xmlhttp.readyState == 4) {
+				createProjectSave(null);
+			} else {
+				popup.showPopup();
+				popup.popupContent.innerHTML = null;
+				popup.popupContent.textContent = "Thank you for performing this listening test";
+			}
+		};
+		xmlhttp.send(file);
+	}
+}
+
+function errorSessionDump(msg){
+	// Create the partial interface XML save
+	// Include error node with message on why the dump occured
+	var xmlDoc = interfaceXMLSave();
+	var err = document.createElement('error');
+	err.textContent = msg;
+	xmlDoc.appendChild(err);
+	var parent = document.createElement("div");
+	parent.appendChild(xmlDoc);
+	var file = [parent.innerHTML];
+	var bb = new Blob(file,{type : 'application/xml'});
+	var dnlk = window.URL.createObjectURL(bb);
+	var a = document.createElement("a");
+	a.hidden = '';
+	a.href = dnlk;
+	a.download = "save.xml";
+	a.textContent = "Save File";
+	
+	popup.showPopup();
+	popup.popupContent.innerHTML = "ERROR : "+msg;
+	popup.popupContent.appendChild(a);
+}
+
+// Only other global function which must be defined in the interface class. Determines how to create the XML document.
+function interfaceXMLSave(){
+	// Create the XML string to be exported with results
+	var xmlDoc = document.createElement("BrowserEvaluationResult");
+	var projectDocument = specification.projectXML;
+	projectDocument.setAttribute('file-name',url);
+	xmlDoc.appendChild(projectDocument);
+	xmlDoc.appendChild(returnDateNode());
+	for (var i=0; i<testState.stateResults.length; i++)
+	{
+		xmlDoc.appendChild(testState.stateResults[i]);
+	}
+	
+	return xmlDoc;
+}
+
+function AudioEngine() {
+	
+	// Create two output paths, the main outputGain and fooGain.
+	// Output gain is default to 1 and any items for playback route here
+	// Foo gain is used for analysis to ensure paths get processed, but are not heard
+	// because web audio will optimise and any route which does not go to the destination gets ignored.
+	this.outputGain = audioContext.createGain();
+	this.fooGain = audioContext.createGain();
+	this.fooGain.gain = 0;
+	
+	// Use this to detect playback state: 0 - stopped, 1 - playing
+	this.status = 0;
+	this.audioObjectsReady = false;
+	
+	// Connect both gains to output
+	this.outputGain.connect(audioContext.destination);
+	this.fooGain.connect(audioContext.destination);
+	
+	// Create the timer Object
+	this.timer = new timer();
+	// Create session metrics
+	this.metric = new sessionMetrics(this);
+	
+	this.loopPlayback = false;
+	
+	// Create store for new audioObjects
+	this.audioObjects = [];
+	
+	this.play = function(id) {
+		// Start the timer and set the audioEngine state to playing (1)
+		if (this.status == 0) {
+			// Check if all audioObjects are ready
+			if (this.audioObjectsReady == false) {
+				this.audioObjectsReady = this.checkAllReady();
+			}
+			if (this.audioObjectsReady == true) {
+				this.timer.startTest();
+				if (this.loopPlayback)
+					{this.setSynchronousLoop();}
+				this.status = 1;
+			}
+		}
+		if (this.status== 1) {
+			if (id == undefined) {
+				id = -1;
+			} else {
+				interfaceContext.playhead.setTimePerPixel(this.audioObjects[id]);
+			}
+			if (this.loopPlayback) {
+				for (var i=0; i<this.audioObjects.length; i++)
+				{
+					this.audioObjects[i].play(this.timer.getTestTime()+1);
+					if (id == i) {
+						this.audioObjects[i].loopStart();
+					} else {
+						this.audioObjects[i].loopStop();
+					}
+				}
+			} else {
+				for (var i=0; i<this.audioObjects.length; i++)
+				{
+					if (i != id) {
+						this.audioObjects[i].outputGain.gain.value = 0.0;
+						this.audioObjects[i].stop();
+					} else if (i == id) {
+						this.audioObjects[id].outputGain.gain.value = 1.0;
+						this.audioObjects[id].play(audioContext.currentTime+0.01);
+					}
+				}
+			}
+			interfaceContext.playhead.start();
+		}
+	};
+	
+	this.stop = function() {
+		// Send stop and reset command to all playback buffers and set audioEngine state to stopped (1)
+		if (this.status == 1) {
+			for (var i=0; i<this.audioObjects.length; i++)
+			{
+				this.audioObjects[i].stop();
+			}
+			interfaceContext.playhead.stop();
+			this.status = 0;
+		}
+	};
+	
+	this.newTrack = function(element) {
+		// Pull data from given URL into new audio buffer
+		// URLs must either be from the same source OR be setup to 'Access-Control-Allow-Origin'
+		
+		// Create the audioObject with ID of the new track length;
+		audioObjectId = this.audioObjects.length;
+		this.audioObjects[audioObjectId] = new audioObject(audioObjectId);
+
+		// AudioObject will get track itself.
+		this.audioObjects[audioObjectId].specification = element;
+		this.audioObjects[audioObjectId].constructTrack(element.parent.hostURL + element.url);
+		return this.audioObjects[audioObjectId];
+	};
+	
+	this.newTestPage = function() {
+		this.state = 0;
+		this.audioObjectsReady = false;
+		this.metric.reset();
+		this.audioObjects = [];
+	};
+	
+	this.checkAllPlayed = function() {
+		arr = [];
+		for (var id=0; id<this.audioObjects.length; id++) {
+			if (this.audioObjects[id].metric.wasListenedTo == false) {
+				arr.push(this.audioObjects[id].id);
+			}
+		}
+		return arr;
+	};
+	
+	this.checkAllReady = function() {
+		var ready = true;
+		for (var i=0; i<this.audioObjects.length; i++) {
+			if (this.audioObjects[i].state == 0) {
+				// Track not ready
+				console.log('WAIT -- audioObject '+i+' not ready yet!');
+				ready = false;
+			};
+		}
+		return ready;
+	};
+	
+	this.setSynchronousLoop = function() {
+		// Pads the signals so they are all exactly the same length
+		if (this.audioObjectsReady)
+		{
+			var length = 0;
+			var lens = [];
+			var maxId;
+			for (var i=0; i<this.audioObjects.length; i++)
+			{
+				lens.push(this.audioObjects[i].buffer.length);
+				if (length < this.audioObjects[i].buffer.length)
+				{
+					length = this.audioObjects[i].buffer.length;
+					maxId = i;
+				}
+			}
+			// Perform difference
+			for (var i=0; i<lens.length; i++)
+			{
+				lens[i] = length - lens[i];
+			}
+			// Extract the audio and zero-pad
+			for (var i=0; i<lens.length; i++)
+			{
+				var orig = this.audioObjects[i].buffer;
+				var hold = audioContext.createBuffer(orig.numberOfChannels,length,orig.sampleRate);
+				for (var c=0; c<orig.numberOfChannels; c++)
+				{
+					var inData = hold.getChannelData(c);
+					var outData = orig.getChannelData(c);
+					for (var n=0; n<orig.length; n++)
+					{inData[n] = outData[n];}
+				}
+				this.audioObjects[i].buffer = hold;
+				delete orig;
+			}
+		}
+	};
+	
+}
+
+function audioObject(id) {
+	// The main buffer object with common control nodes to the AudioEngine
+	
+	this.specification;
+	this.id = id;
+	this.state = 0; // 0 - no data, 1 - ready
+	this.url = null; // Hold the URL given for the output back to the results.
+	this.metric = new metricTracker(this);
+	
+	// Bindings for GUI
+	this.interfaceDOM = null;
+	this.commentDOM = null;
+	
+	// Create a buffer and external gain control to allow internal patching of effects and volume leveling.
+	this.bufferNode = undefined;
+	this.outputGain = audioContext.createGain();
+	
+	// Default output gain to be zero
+	this.outputGain.gain.value = 0.0;
+	
+	// Connect buffer to the audio graph
+	this.outputGain.connect(audioEngineContext.outputGain);
+	
+	// the audiobuffer is not designed for multi-start playback
+	// When stopeed, the buffer node is deleted and recreated with the stored buffer.
+	this.buffer;
+    
+	this.loopStart = function() {
+		this.outputGain.gain.value = 1.0;
+		this.metric.startListening(audioEngineContext.timer.getTestTime());
+	};
+	
+	this.loopStop = function() {
+		if (this.outputGain.gain.value != 0.0) {
+			this.outputGain.gain.value = 0.0;
+			this.metric.stopListening(audioEngineContext.timer.getTestTime());
+		}
+	};
+	
+	this.play = function(startTime) {
+		if (this.bufferNode == undefined) {
+			this.bufferNode = audioContext.createBufferSource();
+			this.bufferNode.owner = this;
+			this.bufferNode.connect(this.outputGain);
+			this.bufferNode.buffer = this.buffer;
+			this.bufferNode.loop = audioEngineContext.loopPlayback;
+			this.bufferNode.onended = function() {
+				// Safari does not like using 'this' to reference the calling object!
+				event.srcElement.owner.metric.stopListening(audioEngineContext.timer.getTestTime(),event.srcElement.owner.getCurrentPosition());
+			};
+			if (this.bufferNode.loop == false) {
+				this.metric.startListening(audioEngineContext.timer.getTestTime());
+			}
+			this.bufferNode.start(startTime);
+		}
+	};
+	
+	this.stop = function() {
+		if (this.bufferNode != undefined)
+		{
+			this.metric.stopListening(audioEngineContext.timer.getTestTime(),this.getCurrentPosition());
+			this.bufferNode.stop(0);
+			this.bufferNode = undefined;
+		}
+	};
+	
+	this.getCurrentPosition = function() {
+		var time = audioEngineContext.timer.getTestTime();
+		if (this.bufferNode != undefined) {
+			if (this.bufferNode.loop == true) {
+				if (audioEngineContext.status  == 1) {
+					return time%this.buffer.duration;
+				} else {
+					return 0;
+				}
+			} else {
+				if (this.metric.listenHold) {
+					return time - this.metric.listenStart;
+				} else {
+					return 0;
+				}
+			}
+		} else {
+			return 0;
+		}
+	};
+
+	this.constructTrack = function(url) {
+		var request = new XMLHttpRequest();
+		this.url = url;
+		request.open('GET',url,true);
+		request.responseType = 'arraybuffer';
+		
+		var audioObj = this;
+		
+		// Create callback to decode the data asynchronously
+		request.onloadend = function() {
+			audioContext.decodeAudioData(request.response, function(decodedData) {
+				audioObj.buffer = decodedData;
+				audioObj.state = 1;
+				if (audioObj.specification.type != 'outsidereference')
+					{audioObj.interfaceDOM.enable();}
+			}, function(){
+				// Should only be called if there was an error, but sometimes gets called continuously
+				// Check here if the error is genuine
+				if (audioObj.state == 0 || audioObj.buffer == undefined) {
+					// Genuine error
+					console.log('FATAL - Error loading buffer on '+audioObj.id);
+					if (request.status == 404)
+					{
+						console.log('FATAL - Fragment '+audioObj.id+' 404 error');
+						console.log('URL: '+audioObj.url);
+						errorSessionDump('Fragment '+audioObj.id+' 404 error');
+					}
+				}
+			});
+		};
+		request.send();
+	};
+	
+	this.exportXMLDOM = function() {
+		var root = document.createElement('audioElement');
+		root.id = this.specification.id;
+		root.setAttribute('url',this.url);
+		var file = document.createElement('file');
+		file.setAttribute('sampleRate',this.buffer.sampleRate);
+		file.setAttribute('channels',this.buffer.numberOfChannels);
+		file.setAttribute('sampleCount',this.buffer.length);
+		file.setAttribute('duration',this.buffer.duration);
+		root.appendChild(file);
+		if (this.specification.type != 'outsidereference') {
+			root.appendChild(this.interfaceDOM.exportXMLDOM(this));
+			root.appendChild(this.commentDOM.exportXMLDOM(this));
+			if(this.specification.type == 'anchor') {
+				root.setAttribute('anchor',true);
+			} else if(this.specification.type == 'reference') {
+				root.setAttribute('reference',true);
+			}
+		}
+		root.appendChild(this.metric.exportXMLDOM());
+		return root;
+	};
+}
+
+function timer()
+{
+	/* Timer object used in audioEngine to keep track of session timings
+	 * Uses the timer of the web audio API, so sample resolution
+	 */
+	this.testStarted = false;
+	this.testStartTime = 0;
+	this.testDuration = 0;
+	this.minimumTestTime = 0; // No minimum test time
+	this.startTest = function()
+	{
+		if (this.testStarted == false)
+		{
+			this.testStartTime = audioContext.currentTime;
+			this.testStarted = true;
+			this.updateTestTime();
+			audioEngineContext.metric.initialiseTest();
+		}
+	};
+	this.stopTest = function()
+	{
+		if (this.testStarted)
+		{
+			this.testDuration = this.getTestTime();
+			this.testStarted = false;
+		} else {
+			console.log('ERR: Test tried to end before beginning');
+		}
+	};
+	this.updateTestTime = function()
+	{
+		if (this.testStarted)
+		{
+			this.testDuration = audioContext.currentTime - this.testStartTime;
+		}
+	};
+	this.getTestTime = function()
+	{
+		this.updateTestTime();
+		return this.testDuration;
+	};
+}
+
+function sessionMetrics(engine)
+{
+	/* Used by audioEngine to link to audioObjects to minimise the timer call timers;
+	 */
+	this.engine = engine;
+	this.lastClicked = -1;
+	this.data = -1;
+	this.reset = function() {
+		this.lastClicked = -1;
+		this.data = -1;
+	};
+	this.initialiseTest = function(){};
+}
+
+function metricTracker(caller)
+{
+	/* Custom object to track and collect metric data
+	 * Used only inside the audioObjects object.
+	 */
+	
+	this.listenedTimer = 0;
+	this.listenStart = 0;
+	this.listenHold = false;
+	this.initialPosition = -1;
+	this.movementTracker = [];
+	this.listenTracker =[];
+	this.wasListenedTo = false;
+	this.wasMoved = false;
+	this.hasComments = false;
+	this.parent = caller;
+	
+	this.initialised = function(position)
+	{
+		if (this.initialPosition == -1) {
+			this.initialPosition = position;
+		}
+	};
+	
+	this.moved = function(time,position)
+	{
+		this.wasMoved = true;
+		this.movementTracker[this.movementTracker.length] = [time, position];
+	};
+	
+	this.startListening = function(time)
+	{
+		if (this.listenHold == false)
+		{
+			this.wasListenedTo = true;
+			this.listenStart = time;
+			this.listenHold = true;
+			
+			var evnt = document.createElement('event');
+			var testTime = document.createElement('testTime');
+			testTime.setAttribute('start',time);
+			var bufferTime = document.createElement('bufferTime');
+			bufferTime.setAttribute('start',this.parent.getCurrentPosition());
+			evnt.appendChild(testTime);
+			evnt.appendChild(bufferTime);
+			this.listenTracker.push(evnt);
+			
+			console.log('slider ' + this.parent.id + ' played (' + time + ')'); // DEBUG/SAFETY: show played slider id
+		}
+	};
+	
+	this.stopListening = function(time,bufferStopTime)
+	{
+		if (this.listenHold == true)
+		{
+			var diff = time - this.listenStart;
+			this.listenedTimer += (diff);
+			this.listenStart = 0;
+			this.listenHold = false;
+			
+			var evnt = this.listenTracker[this.listenTracker.length-1];
+			var testTime = evnt.getElementsByTagName('testTime')[0];
+			var bufferTime = evnt.getElementsByTagName('bufferTime')[0];
+			testTime.setAttribute('stop',time);
+			if (bufferStopTime == undefined) {
+				bufferTime.setAttribute('stop',this.parent.getCurrentPosition());
+			} else {
+				bufferTime.setAttribute('stop',bufferStopTime);
+			}
+			console.log('slider ' + this.parent.id + ' played for (' + diff + ')'); // DEBUG/SAFETY: show played slider id
+		}
+	};
+	
+	this.exportXMLDOM = function() {
+		var root = document.createElement('metric');
+		if (audioEngineContext.metric.enableElementTimer) {
+			var mElementTimer = document.createElement('metricresult');
+			mElementTimer.setAttribute('name','enableElementTimer');
+			mElementTimer.textContent = this.listenedTimer;
+			root.appendChild(mElementTimer);
+		}
+		if (audioEngineContext.metric.enableElementTracker) {
+			var elementTrackerFull = document.createElement('metricResult');
+			elementTrackerFull.setAttribute('name','elementTrackerFull');
+			for (var k=0; k<this.movementTracker.length; k++)
+			{
+				var timePos = document.createElement('timePos');
+				timePos.id = k;
+				var time = document.createElement('time');
+				time.textContent = this.movementTracker[k][0];
+				var position = document.createElement('position');
+				position.textContent = this.movementTracker[k][1];
+				timePos.appendChild(time);
+				timePos.appendChild(position);
+				elementTrackerFull.appendChild(timePos);
+			}
+			root.appendChild(elementTrackerFull);
+		}
+		if (audioEngineContext.metric.enableElementListenTracker) {
+			var elementListenTracker = document.createElement('metricResult');
+			elementListenTracker.setAttribute('name','elementListenTracker');
+			for (var k=0; k<this.listenTracker.length; k++) {
+				elementListenTracker.appendChild(this.listenTracker[k]);
+			}
+			root.appendChild(elementListenTracker);
+		}
+		if (audioEngineContext.metric.enableElementInitialPosition) {
+			var elementInitial = document.createElement('metricResult');
+			elementInitial.setAttribute('name','elementInitialPosition');
+			elementInitial.textContent = this.initialPosition;
+			root.appendChild(elementInitial);
+		}
+		if (audioEngineContext.metric.enableFlagListenedTo) {
+			var flagListenedTo = document.createElement('metricResult');
+			flagListenedTo.setAttribute('name','elementFlagListenedTo');
+			flagListenedTo.textContent = this.wasListenedTo;
+			root.appendChild(flagListenedTo);
+		}
+		if (audioEngineContext.metric.enableFlagMoved) {
+			var flagMoved = document.createElement('metricResult');
+			flagMoved.setAttribute('name','elementFlagMoved');
+			flagMoved.textContent = this.wasMoved;
+			root.appendChild(flagMoved);
+		}
+		if (audioEngineContext.metric.enableFlagComments) {
+			var flagComments = document.createElement('metricResult');
+			flagComments.setAttribute('name','elementFlagComments');
+			if (this.parent.commentDOM == null)
+				{flag.textContent = 'false';}
+			else if (this.parent.commentDOM.textContent.length == 0) 
+				{flag.textContent = 'false';}
+			else 
+				{flag.textContet = 'true';}
+			root.appendChild(flagComments);
+		}
+		
+		return root;
+	};
+}
+
+function randomiseOrder(input)
+{
+	// This takes an array of information and randomises the order
+	var N = input.length;
+	
+	var inputSequence = []; // For safety purposes: keep track of randomisation
+	for (var counter = 0; counter < N; ++counter) 
+		inputSequence.push(counter) // Fill array
+	var inputSequenceClone = inputSequence.slice(0);
+	
+	var holdArr = [];
+	var outputSequence = [];
+	for (var n=0; n<N; n++)
+	{
+		// First pick a random number
+		var r = Math.random();
+		// Multiply and floor by the number of elements left
+		r = Math.floor(r*input.length);
+		// Pick out that element and delete from the array
+		holdArr.push(input.splice(r,1)[0]);
+		// Do the same with sequence
+		outputSequence.push(inputSequence.splice(r,1)[0]);
+	}
+	console.log(inputSequenceClone.toString()); // print original array to console
+	console.log(outputSequence.toString()); 	// print randomised array to console
+	return holdArr;
+}
+
+function returnDateNode()
+{
+	// Create an XML Node for the Date and Time a test was conducted
+	// Structure is
+	// <datetime> 
+	//	<date year="##" month="##" day="##">DD/MM/YY</date>
+	//	<time hour="##" minute="##" sec="##">HH:MM:SS</time>
+	// </datetime>
+	var dateTime = new Date();
+	var year = document.createAttribute('year');
+	var month = document.createAttribute('month');
+	var day = document.createAttribute('day');
+	var hour = document.createAttribute('hour');
+	var minute = document.createAttribute('minute');
+	var secs = document.createAttribute('secs');
+	
+	year.nodeValue = dateTime.getFullYear();
+	month.nodeValue = dateTime.getMonth()+1;
+	day.nodeValue = dateTime.getDate();
+	hour.nodeValue = dateTime.getHours();
+	minute.nodeValue = dateTime.getMinutes();
+	secs.nodeValue = dateTime.getSeconds();
+	
+	var hold = document.createElement("datetime");
+	var date = document.createElement("date");
+	date.textContent = year.nodeValue+'/'+month.nodeValue+'/'+day.nodeValue;
+	var time = document.createElement("time");
+	time.textContent = hour.nodeValue+':'+minute.nodeValue+':'+secs.nodeValue;
+	
+	date.setAttributeNode(year);
+	date.setAttributeNode(month);
+	date.setAttributeNode(day);
+	time.setAttributeNode(hour);
+	time.setAttributeNode(minute);
+	time.setAttributeNode(secs);
+	
+	hold.appendChild(date);
+	hold.appendChild(time);
+	return hold
+	
+}
+
+function testWaitIndicator() {
+	if (audioEngineContext.checkAllReady() == false) {
+		var hold = document.createElement("div");
+		hold.id = "testWaitIndicator";
+		hold.className = "indicator-box";
+		hold.style.zIndex = 3;
+		var span = document.createElement("span");
+		span.textContent = "Please wait! Elements still loading";
+		hold.appendChild(span);
+		var blank = document.createElement('div');
+		blank.className = 'testHalt';
+		blank.id = "testHaltBlank";
+		var body = document.getElementsByTagName('body')[0];
+		body.appendChild(hold);
+		body.appendChild(blank);
+		testWaitTimerIntervalHolder = setInterval(function(){
+			var ready = audioEngineContext.checkAllReady();
+			if (ready) {
+				var elem = document.getElementById('testWaitIndicator');
+				var blank = document.getElementById('testHaltBlank');
+				var body = document.getElementsByTagName('body')[0];
+				body.removeChild(elem);
+				body.removeChild(blank);
+				clearInterval(testWaitTimerIntervalHolder);
+			}
+		},500,false);
+	}
+}
+
+var testWaitTimerIntervalHolder = null;
+
+function Specification() {
+	// Handles the decoding of the project specification XML into a simple JavaScript Object.
+	
+	this.interfaceType;
+	this.commonInterface;
+	this.projectReturn;
+	this.randomiseOrder;
+	this.collectMetrics;
+	this.preTest;
+	this.postTest;
+	this.metrics =[];
+	
+	this.audioHolders = [];
+	
+	this.decode = function() {
+		// projectXML - DOM Parsed document
+		this.projectXML = projectXML.childNodes[0];
+		var setupNode = projectXML.getElementsByTagName('setup')[0];
+		this.interfaceType = setupNode.getAttribute('interface');
+		this.projectReturn = setupNode.getAttribute('projectReturn');
+		if (setupNode.getAttribute('randomiseOrder') == "true") {
+			this.randomiseOrder = true;
+		} else {this.randomiseOrder = false;}
+		if (setupNode.getAttribute('collectMetrics') == "true") {
+			this.collectMetrics = true;
+		} else {this.collectMetrics = false;}
+		var metricCollection = setupNode.getElementsByTagName('Metric');
+		
+		this.preTest = new this.prepostNode('pretest',setupNode.getElementsByTagName('PreTest'));
+		this.postTest = new this.prepostNode('posttest',setupNode.getElementsByTagName('PostTest'));
+		
+		if (metricCollection.length > 0) {
+			metricCollection = metricCollection[0].getElementsByTagName('metricEnable');
+			for (var i=0; i<metricCollection.length; i++) {
+				this.metrics.push(new this.metricNode(metricCollection[i].textContent));
+			}
+		}
+		
+		var commonInterfaceNode = setupNode.getElementsByTagName('interface');
+		if (commonInterfaceNode.length > 0) {
+			commonInterfaceNode = commonInterfaceNode[0];
+		} else {
+			commonInterfaceNode = undefined;
+		}
+		
+		this.commonInterface = new function() {
+			this.OptionNode = function(child) {
+				this.type = child.nodeName;
+				if (this.type == 'option')
+				{
+					this.name = child.getAttribute('name');
+				}
+				else if (this.type == 'check') {
+					this.check = child.getAttribute('name');
+					if (this.check == 'scalerange') {
+						this.min = child.getAttribute('min');
+						this.max = child.getAttribute('max');
+						if (this.min == null) {this.min = 1;}
+						else if (Number(this.min) > 1 && this.min != null) {
+							this.min = Number(this.min)/100;
+						} else {
+							this.min = Number(this.min);
+						}
+						if (this.max == null) {this.max = 0;}
+						else if (Number(this.max) > 1 && this.max != null) {
+							this.max = Number(this.max)/100;
+						} else {
+							this.max = Number(this.max);
+						}
+					}
+				} else if (this.type == 'anchor' || this.type == 'reference') {
+					this.value = Number(child.textContent);
+					this.enforce = child.getAttribute('enforce');
+					if (this.enforce == 'true') {this.enforce = true;}
+					else {this.enforce = false;}
+				}
+			};
+			this.options = [];
+			if (commonInterfaceNode != undefined) {
+				var child = commonInterfaceNode.firstElementChild;
+				while (child != undefined) {
+					this.options.push(new this.OptionNode(child));
+					child = child.nextElementSibling;
+				}
+			}
+		};
+		
+		var audioHolders = projectXML.getElementsByTagName('audioHolder');
+		for (var i=0; i<audioHolders.length; i++) {
+			this.audioHolders.push(new this.audioHolderNode(this,audioHolders[i]));
+		}
+		
+	};
+	
+	this.prepostNode = function(type,Collection) {
+		this.type = type;
+		this.options = [];
+		
+		this.OptionNode = function(child) {
+			
+			this.childOption = function(element) {
+				this.type = 'option';
+				this.id = element.id;
+				this.name = element.getAttribute('name');
+				this.text = element.textContent;
+			};
+			
+			this.type = child.nodeName;
+			if (child.nodeName == "question") {
+				this.id = child.id;
+				this.mandatory;
+				if (child.getAttribute('mandatory') == "true") {this.mandatory = true;}
+				else {this.mandatory = false;}
+				this.question = child.textContent;
+				if (child.getAttribute('boxsize') == null) {
+					this.boxsize = 'normal';
+				} else {
+					this.boxsize = child.getAttribute('boxsize');
+				}
+			} else if (child.nodeName == "statement") {
+				this.statement = child.textContent;
+			} else if (child.nodeName == "checkbox" || child.nodeName == "radio") {
+				var element = child.firstElementChild;
+				this.id = child.id;
+				if (element == null) {
+					console.log('Malformed' +child.nodeName+ 'entry');
+					this.statement = 'Malformed' +child.nodeName+ 'entry';
+					this.type = 'statement';
+				} else {
+					this.options = [];
+					while (element != null) {
+						if (element.nodeName == 'statement' && this.statement == undefined){
+							this.statement = element.textContent;
+						} else if (element.nodeName == 'option') {
+							this.options.push(new this.childOption(element));
+						}
+						element = element.nextElementSibling;
+					}
+				}
+			} else if (child.nodeName == "number") {
+				this.statement = child.textContent;
+				this.id = child.id;
+				this.min = child.getAttribute('min');
+				this.max = child.getAttribute('max');
+				this.step = child.getAttribute('step');
+			}
+		};
+		
+		// On construction:
+		if (Collection.length != 0) {
+			Collection = Collection[0];
+			if (Collection.childElementCount != 0) {
+				var child = Collection.firstElementChild;
+				this.options.push(new this.OptionNode(child));
+				while (child.nextElementSibling != null) {
+					child = child.nextElementSibling;
+					this.options.push(new this.OptionNode(child));
+				}
+			}
+		}
+	};
+	
+	this.metricNode = function(name) {
+		this.enabled = name;
+	};
+	
+	this.audioHolderNode = function(parent,xml) {
+		this.type = 'audioHolder';
+		this.presentedId = parent.audioHolders.length;
+		this.interfaceNode = function(DOM) {
+			var title = DOM.getElementsByTagName('title');
+			if (title.length == 0) {this.title = null;}
+			else {this.title = title[0].textContent;}
+			this.options = parent.commonInterface.options;
+			var scale = DOM.getElementsByTagName('scale');
+			this.scale = [];
+			for (var i=0; i<scale.length; i++) {
+				var arr = [null, null];
+				arr[0] = scale[i].getAttribute('position');
+				arr[1] = scale[i].textContent;
+				this.scale.push(arr);
+			}
+		};
+		
+		this.audioElementNode = function(parent,xml) {
+			this.url = xml.getAttribute('url');
+			this.id = xml.id;
+			this.parent = parent;
+			this.type = xml.getAttribute('type');
+			if (this.type == null) {this.type = "normal";}
+			if (this.type == 'anchor') {this.anchor = true;}
+			else {this.anchor = false;}
+			if (this.type == 'reference') {this.reference = true;}
+			else {this.reference = false;}
+			
+			this.marker = xml.getAttribute('marker');
+			if (this.marker == null) {this.marker = undefined;}
+			
+			if (this.anchor == true) {
+				if (this.marker != undefined) {this.enforce = true;}
+				else {this.enforce = enforceAnchor;}
+				this.marker = anchor;
+			}
+			else if (this.reference == true) {
+				if (this.marker != undefined) {this.enforce = true;}
+				else {this.enforce = enforceReference;}
+				this.marker = reference;
+			}
+			
+			if (this.marker != undefined) {
+				this.marker = Number(this.marker);
+				if (this.marker > 1) {this.marker /= 100;}
+			}
+		};
+		
+		this.commentQuestionNode = function(xml) {
+			this.childOption = function(element) {
+				this.type = 'option';
+				this.name = element.getAttribute('name');
+				this.text = element.textContent;
+			};
+			this.id = xml.id;
+			if (xml.getAttribute('mandatory') == 'true') {this.mandatory = true;}
+			else {this.mandatory = false;}
+			this.type = xml.getAttribute('type');
+			if (this.type == undefined) {this.type = 'text';}
+			switch (this.type) {
+			case 'text':
+				this.question = xml.textContent;
+				break;
+			case 'radio':
+				var child = xml.firstElementChild;
+				this.options = [];
+				while (child != undefined) {
+					if (child.nodeName == 'statement' && this.statement == undefined) {
+						this.statement = child.textContent;
+					} else if (child.nodeName == 'option') {
+						this.options.push(new this.childOption(child));
+					}
+					child = child.nextElementSibling;
+				}
+				break;
+			case 'checkbox':
+				var child = xml.firstElementChild;
+				this.options = [];
+				while (child != undefined) {
+					if (child.nodeName == 'statement' && this.statement == undefined) {
+						this.statement = child.textContent;
+					} else if (child.nodeName == 'option') {
+						this.options.push(new this.childOption(child));
+					}
+					child = child.nextElementSibling;
+				}
+				break;
+			}
+		};
+		
+		this.id = xml.id;
+		this.hostURL = xml.getAttribute('hostURL');
+		this.sampleRate = xml.getAttribute('sampleRate');
+		if (xml.getAttribute('randomiseOrder') == "true") {this.randomiseOrder = true;}
+		else {this.randomiseOrder = false;}
+		this.repeatCount = xml.getAttribute('repeatCount');
+		if (xml.getAttribute('loop') == 'true') {this.loop = true;}
+		else {this.loop == false;}
+		if (xml.getAttribute('elementComments') == "true") {this.elementComments = true;}
+		else {this.elementComments = false;}
+		
+		var anchor = xml.getElementsByTagName('anchor');
+		var enforceAnchor = false;
+		if (anchor.length == 0) {
+			// Find anchor in commonInterface;
+			for (var i=0; i<parent.commonInterface.options.length; i++) {
+				if(parent.commonInterface.options[i].type == 'anchor') {
+					anchor = parent.commonInterface.options[i].value;
+					enforceAnchor = parent.commonInterface.options[i].enforce;
+					break;
+				}
+			}
+			if (typeof(anchor) == "object") {
+				anchor = null;
+			}
+		} else {
+			anchor = anchor[0].textContent;
+		}
+		
+		var reference = xml.getElementsByTagName('anchor');
+		var enforceReference = false;
+		if (reference.length == 0) {
+			// Find anchor in commonInterface;
+			for (var i=0; i<parent.commonInterface.options.length; i++) {
+				if(parent.commonInterface.options[i].type == 'reference') {
+					reference = parent.commonInterface.options[i].value;
+					enforceReference = parent.commonInterface.options[i].enforce;
+					break;
+				}
+			}
+			if (typeof(reference) == "object") {
+				reference = null;
+			}
+		} else {
+			reference = reference[0].textContent;
+		}
+		
+		if (typeof(anchor) == 'number') {
+			if (anchor > 1 && anchor < 100) {anchor /= 100.0;}
+		}
+		
+		if (typeof(reference) == 'number') {
+			if (reference > 1 && reference < 100) {reference /= 100.0;}
+		}
+		
+		this.preTest = new parent.prepostNode('pretest',xml.getElementsByTagName('PreTest'));
+		this.postTest = new parent.prepostNode('posttest',xml.getElementsByTagName('PostTest'));
+		
+		this.interfaces = [];
+		var interfaceDOM = xml.getElementsByTagName('interface');
+		for (var i=0; i<interfaceDOM.length; i++) {
+			this.interfaces.push(new this.interfaceNode(interfaceDOM[i]));
+		}
+		
+		this.commentBoxPrefix = xml.getElementsByTagName('commentBoxPrefix');
+		if (this.commentBoxPrefix.length != 0) {
+			this.commentBoxPrefix = this.commentBoxPrefix[0].textContent;
+		} else {
+			this.commentBoxPrefix = "Comment on track";
+		}
+		
+		this.audioElements  =[];
+		var audioElementsDOM = xml.getElementsByTagName('audioElements');
+		this.outsideReference = null;
+		for (var i=0; i<audioElementsDOM.length; i++) {
+			if (audioElementsDOM[i].getAttribute('type') == 'outsidereference') {
+				if (this.outsideReference == null) {
+					this.outsideReference = new this.audioElementNode(this,audioElementsDOM[i]);
+				} else {
+					console.log('Error only one audioelement can be of type outsidereference per audioholder');
+					this.audioElements.push(new this.audioElementNode(this,audioElementsDOM[i]));
+					console.log('Element id '+audioElementsDOM[i].id+' made into normal node');
+				}
+			} else {
+				this.audioElements.push(new this.audioElementNode(this,audioElementsDOM[i]));
+			}
+		}
+		
+		if (this.randomiseOrder) {
+			this.audioElements = randomiseOrder(this.audioElements);
+		}
+		
+		// Check only one anchor and one reference per audioNode
+		var anchor = [];
+		var reference = [];
+		this.anchorId = null;
+		this.referenceId = null;
+		for (var i=0; i<this.audioElements.length; i++)
+		{
+			if (this.audioElements[i].anchor == true) {anchor.push(i);}
+			if (this.audioElements[i].reference == true) {reference.push(i);}
+		}
+		
+		if (anchor.length > 1) {
+			console.log('Error - cannot have more than one anchor!');
+			console.log('Each anchor node will be a normal mode to continue the test');
+			for (var i=0; i<anchor.length; i++)
+			{
+				this.audioElements[anchor[i]].anchor = false;
+				this.audioElements[anchor[i]].value = undefined;
+			}
+		} else {this.anchorId = anchor[0];}
+		if (reference.length > 1) {
+			console.log('Error - cannot have more than one anchor!');
+			console.log('Each anchor node will be a normal mode to continue the test');
+			for (var i=0; i<reference.length; i++)
+			{
+				this.audioElements[reference[i]].reference = false;
+				this.audioElements[reference[i]].value = undefined;
+			}
+		} else {this.referenceId = reference[0];}
+		
+		this.commentQuestions = [];
+		var commentQuestionsDOM = xml.getElementsByTagName('CommentQuestion');
+		for (var i=0; i<commentQuestionsDOM.length; i++) {
+			this.commentQuestions.push(new this.commentQuestionNode(commentQuestionsDOM[i]));
+		}
+	};
+}
+
+function Interface(specificationObject) {
+	// This handles the bindings between the interface and the audioEngineContext;
+	this.specification = specificationObject;
+	this.insertPoint = document.getElementById("topLevelBody");
+	
+	// Bounded by interface!!
+	// Interface object MUST have an exportXMLDOM method which returns the various DOM levels
+	// For example, APE returns  the slider position normalised in a <value> tag.
+	this.interfaceObjects = [];
+	this.interfaceObject = function(){};
+	
+	this.commentBoxes = [];
+	this.elementCommentBox = function(audioObject) {
+		var element = audioObject.specification;
+		this.audioObject = audioObject;
+		this.id = audioObject.id;
+		var audioHolderObject = audioObject.specification.parent;
+		// Create document objects to hold the comment boxes
+		this.trackComment = document.createElement('div');
+		this.trackComment.className = 'comment-div';
+		this.trackComment.id = 'comment-div-'+audioObject.id;
+		// Create a string next to each comment asking for a comment
+		this.trackString = document.createElement('span');
+		this.trackString.innerHTML = audioHolderObject.commentBoxPrefix+' '+audioObject.id;
+		// Create the HTML5 comment box 'textarea'
+		this.trackCommentBox = document.createElement('textarea');
+		this.trackCommentBox.rows = '4';
+		this.trackCommentBox.cols = '100';
+		this.trackCommentBox.name = 'trackComment'+audioObject.id;
+		this.trackCommentBox.className = 'trackComment';
+		var br = document.createElement('br');
+		// Add to the holder.
+		this.trackComment.appendChild(this.trackString);
+		this.trackComment.appendChild(br);
+		this.trackComment.appendChild(this.trackCommentBox);
+		
+		this.exportXMLDOM = function() {
+			var root = document.createElement('comment');
+			if (this.audioObject.specification.parent.elementComments) {
+				var question = document.createElement('question');
+				question.textContent = this.trackString.textContent;
+				var response = document.createElement('response');
+				response.textContent = this.trackCommentBox.value;
+				console.log("Comment frag-"+this.id+": "+response.textContent);
+				root.appendChild(question);
+				root.appendChild(response);
+			}
+			return root;
+		};
+	};
+	
+	this.commentQuestions = [];
+	
+	this.commentBox = function(commentQuestion) {
+		this.specification = commentQuestion;
+		// Create document objects to hold the comment boxes
+		this.holder = document.createElement('div');
+		this.holder.className = 'comment-div';
+		// Create a string next to each comment asking for a comment
+		this.string = document.createElement('span');
+		this.string.innerHTML = commentQuestion.question;
+		// Create the HTML5 comment box 'textarea'
+		this.textArea = document.createElement('textarea');
+		this.textArea.rows = '4';
+		this.textArea.cols = '100';
+		this.textArea.className = 'trackComment';
+		var br = document.createElement('br');
+		// Add to the holder.
+		this.holder.appendChild(this.string);
+		this.holder.appendChild(br);
+		this.holder.appendChild(this.textArea);
+		
+		this.exportXMLDOM = function() {
+			var root = document.createElement('comment');
+			root.id = this.specification.id;
+			root.setAttribute('type',this.specification.type);
+			root.textContent = this.textArea.value;
+			console.log("Question: "+this.string.textContent);
+			console.log("Response: "+root.textContent);
+			return root;
+		};
+	};
+	
+	this.radioBox = function(commentQuestion) {
+		this.specification = commentQuestion;
+		// Create document objects to hold the comment boxes
+		this.holder = document.createElement('div');
+		this.holder.className = 'comment-div';
+		// Create a string next to each comment asking for a comment
+		this.string = document.createElement('span');
+		this.string.innerHTML = commentQuestion.statement;
+		var br = document.createElement('br');
+		// Add to the holder.
+		this.holder.appendChild(this.string);
+		this.holder.appendChild(br);
+		this.options = [];
+		this.inputs = document.createElement('div');
+		this.span = document.createElement('div');
+		this.inputs.align = 'center';
+		this.inputs.style.marginLeft = '12px';
+		this.span.style.marginLeft = '12px';
+		this.span.align = 'center';
+		this.span.style.marginTop = '15px';
+		
+		var optCount = commentQuestion.options.length;
+		var spanMargin = Math.floor(((600-(optCount*100))/(optCount))/2)+'px';
+		console.log(spanMargin);
+		for (var i=0; i<optCount; i++)
+		{
+			var div = document.createElement('div');
+			div.style.width = '100px';
+			div.style.float = 'left';
+			div.style.marginRight = spanMargin;
+			div.style.marginLeft = spanMargin;
+			var input = document.createElement('input');
+			input.type = 'radio';
+			input.name = commentQuestion.id;
+			input.setAttribute('setvalue',commentQuestion.options[i].name);
+			input.className = 'comment-radio';
+			div.appendChild(input);
+			this.inputs.appendChild(div);
+			
+			
+			div = document.createElement('div');
+			div.style.width = '100px';
+			div.style.float = 'left';
+			div.style.marginRight = spanMargin;
+			div.style.marginLeft = spanMargin;
+			div.align = 'center';
+			var span = document.createElement('span');
+			span.textContent = commentQuestion.options[i].text;
+			span.className = 'comment-radio-span';
+			div.appendChild(span);
+			this.span.appendChild(div);
+			this.options.push(input);
+		}
+		this.holder.appendChild(this.span);
+		this.holder.appendChild(this.inputs);
+		
+		this.exportXMLDOM = function() {
+			var root = document.createElement('comment');
+			root.id = this.specification.id;
+			root.setAttribute('type',this.specification.type);
+			var question = document.createElement('question');
+			question.textContent = this.string.textContent;
+			var response = document.createElement('response');
+			var i=0;
+			while(this.options[i].checked == false) {
+				i++;
+				if (i >= this.options.length) {
+					break;
+				}
+			}
+			if (i >= this.options.length) {
+				response.textContent = 'null';
+			} else {
+				response.textContent = this.options[i].getAttribute('setvalue');
+				response.setAttribute('number',i);
+			}
+			console.log('Comment: '+question.textContent);
+			console.log('Response: '+response.textContent);
+			root.appendChild(question);
+			root.appendChild(response);
+			return root;
+		};
+	};
+	
+	this.checkboxBox = function(commentQuestion) {
+		this.specification = commentQuestion;
+		// Create document objects to hold the comment boxes
+		this.holder = document.createElement('div');
+		this.holder.className = 'comment-div';
+		// Create a string next to each comment asking for a comment
+		this.string = document.createElement('span');
+		this.string.innerHTML = commentQuestion.statement;
+		var br = document.createElement('br');
+		// Add to the holder.
+		this.holder.appendChild(this.string);
+		this.holder.appendChild(br);
+		this.options = [];
+		this.inputs = document.createElement('div');
+		this.span = document.createElement('div');
+		this.inputs.align = 'center';
+		this.inputs.style.marginLeft = '12px';
+		this.span.style.marginLeft = '12px';
+		this.span.align = 'center';
+		this.span.style.marginTop = '15px';
+		
+		var optCount = commentQuestion.options.length;
+		var spanMargin = Math.floor(((600-(optCount*100))/(optCount))/2)+'px';
+		console.log(spanMargin);
+		for (var i=0; i<optCount; i++)
+		{
+			var div = document.createElement('div');
+			div.style.width = '100px';
+			div.style.float = 'left';
+			div.style.marginRight = spanMargin;
+			div.style.marginLeft = spanMargin;
+			var input = document.createElement('input');
+			input.type = 'checkbox';
+			input.name = commentQuestion.id;
+			input.setAttribute('setvalue',commentQuestion.options[i].name);
+			input.className = 'comment-radio';
+			div.appendChild(input);
+			this.inputs.appendChild(div);
+			
+			
+			div = document.createElement('div');
+			div.style.width = '100px';
+			div.style.float = 'left';
+			div.style.marginRight = spanMargin;
+			div.style.marginLeft = spanMargin;
+			div.align = 'center';
+			var span = document.createElement('span');
+			span.textContent = commentQuestion.options[i].text;
+			span.className = 'comment-radio-span';
+			div.appendChild(span);
+			this.span.appendChild(div);
+			this.options.push(input);
+		}
+		this.holder.appendChild(this.span);
+		this.holder.appendChild(this.inputs);
+		
+		this.exportXMLDOM = function() {
+			var root = document.createElement('comment');
+			root.id = this.specification.id;
+			root.setAttribute('type',this.specification.type);
+			var question = document.createElement('question');
+			question.textContent = this.string.textContent;
+			root.appendChild(question);
+			console.log('Comment: '+question.textContent);
+			for (var i=0; i<this.options.length; i++) {
+				var response = document.createElement('response');
+				response.textContent = this.options[i].checked;
+				response.setAttribute('name',this.options[i].getAttribute('setvalue'));
+				root.appendChild(response);
+				console.log('Response '+response.getAttribute('name') +': '+response.textContent);
+			}
+			return root;
+		};
+	};
+
+	this.createCommentBox = function(audioObject) {
+		var node = new this.elementCommentBox(audioObject);
+		this.commentBoxes.push(node);
+		audioObject.commentDOM = node;
+		return node;
+	};
+	
+	this.sortCommentBoxes = function() {
+		var holder = [];
+		while (this.commentBoxes.length > 0) {
+			var node = this.commentBoxes.pop(0);
+			holder[node.id] = node;
+		}
+		this.commentBoxes = holder;
+	};
+	
+	this.showCommentBoxes = function(inject, sort) {
+		if (sort) {interfaceContext.sortCommentBoxes();}
+		for (var i=0; i<interfaceContext.commentBoxes.length; i++) {
+			inject.appendChild(this.commentBoxes[i].trackComment);
+		}
+	};
+	
+	this.deleteCommentBoxes = function() {
+		this.commentBoxes = [];
+	};
+	
+	this.createCommentQuestion = function(element) {
+		var node;
+		if (element.type == 'text') {
+			node = new this.commentBox(element);
+		} else if (element.type == 'radio') {
+			node = new this.radioBox(element);
+		} else if (element.type == 'checkbox') {
+			node = new this.checkboxBox(element);
+		}
+		this.commentQuestions.push(node);
+		return node;
+	};
+	
+	this.deleteCommentQuestions = function()
+	{
+		this.commentQuestions = [];
+	};
+	
+	this.playhead = new function()
+	{
+		this.object = document.createElement('div');
+		this.object.className = 'playhead';
+		this.object.align = 'left';
+		var curTime = document.createElement('div');
+		curTime.style.width = '50px';
+		this.curTimeSpan = document.createElement('span');
+		this.curTimeSpan.textContent = '00:00';
+		curTime.appendChild(this.curTimeSpan);
+		this.object.appendChild(curTime);
+		this.scrubberTrack = document.createElement('div');
+		this.scrubberTrack.className = 'playhead-scrub-track';
+		
+		this.scrubberHead = document.createElement('div');
+		this.scrubberHead.id = 'playhead-scrubber';
+		this.scrubberTrack.appendChild(this.scrubberHead);
+		this.object.appendChild(this.scrubberTrack);
+		
+		this.timePerPixel = 0;
+		this.maxTime = 0;
+		
+		this.playbackObject;
+		
+		this.setTimePerPixel = function(audioObject) {
+			//maxTime must be in seconds
+			this.playbackObject = audioObject;
+			this.maxTime = audioObject.buffer.duration;
+			var width = 490; //500 - 10, 5 each side of the tracker head
+			this.timePerPixel = this.maxTime/490;
+			if (this.maxTime < 60) {
+				this.curTimeSpan.textContent = '0.00';
+			} else {
+				this.curTimeSpan.textContent = '00:00';
+			}
+		};
+		
+		this.update = function() {
+			// Update the playhead position, startPlay must be called
+			if (this.timePerPixel > 0) {
+				var time = this.playbackObject.getCurrentPosition();
+				if (time > 0) {
+					var width = 490;
+					var pix = Math.floor(time/this.timePerPixel);
+					this.scrubberHead.style.left = pix+'px';
+					if (this.maxTime > 60.0) {
+						var secs = time%60;
+						var mins = Math.floor((time-secs)/60);
+						secs = secs.toString();
+						secs = secs.substr(0,2);
+						mins = mins.toString();
+						this.curTimeSpan.textContent = mins+':'+secs;
+					} else {
+						time = time.toString();
+						this.curTimeSpan.textContent = time.substr(0,4);
+					}
+				} else {
+					this.scrubberHead.style.left = '0px';
+					if (this.maxTime < 60) {
+						this.curTimeSpan.textContent = '0.00';
+					} else {
+						this.curTimeSpan.textContent = '00:00';
+					}
+				}
+			}
+		};
+		
+		this.interval = undefined;
+		
+		this.start = function() {
+			if (this.playbackObject != undefined && this.interval == undefined) {
+				if (this.maxTime < 60) {
+					this.interval = setInterval(function(){interfaceContext.playhead.update();},10);
+				} else {
+					this.interval = setInterval(function(){interfaceContext.playhead.update();},100);
+				}
+			}
+		};
+		this.stop = function() {
+			clearInterval(this.interval);
+			this.interval = undefined;
+			if (this.maxTime < 60) {
+				this.curTimeSpan.textContent = '0.00';
+			} else {
+				this.curTimeSpan.textContent = '00:00';
+			}
+		};
+	};
+	
+	// Global Checkers
+	// These functions will help enforce the checkers
+	this.checkHiddenAnchor = function()
+	{
+		var audioHolder = testState.currentStateMap[testState.currentIndex];
+		if (audioHolder.anchorId != null)
+		{
+			var audioObject = audioEngineContext.audioObjects[audioHolder.anchorId];
+			if (audioObject.interfaceDOM.getValue() > audioObject.specification.marker && audioObject.interfaceDOM.enforce == true)
+			{
+				// Anchor is not set below
+				console.log('Anchor node not below marker value');
+				alert('Please keep listening');
+				return false;
+			}
+		}
+		return true;
+	};
+	
+	this.checkHiddenReference = function()
+	{
+		var audioHolder = testState.currentStateMap[testState.currentIndex];
+		if (audioHolder.referenceId != null)
+		{
+			var audioObject = audioEngineContext.audioObjects[audioHolder.referenceId];
+			if (audioObject.interfaceDOM.getValue() < audioObject.specification.marker && audioObject.interfaceDOM.enforce == true)
+			{
+				// Anchor is not set below
+				console.log('Reference node not above marker value');
+				alert('Please keep listening');
+				return false;
+			}
+		}
+		return true;
+	};
+}