snowplow.js

/*!
 * SnowPlow - The world’s most powerful web analytics platform
 *
 * @description JavaScript tracking client for SnowPlow
 * @version 0.4
 * @author Alex Dean, Anthon Pang
 */

// Refer to /docs/04_selfhosting_snowplow.md for instructions on how to minify this file for distribution.

/*
 * Browser [In]Compatibility
 * - minimum required ECMAScript: ECMA-262, edition 3
 *
 * Incompatible with these (and earlier) versions of:
 * - IE4 - try..catch and for..in introduced in IE5
 * - IE5 - named anonymous functions, array.push, encodeURIComponent, decodeURIComponent, and getElementsByTagName introduced in IE5.5
 * - Firefox 1.0 and Netscape 8.x - FF1.5 adds array.indexOf, among other things
 * - Mozilla 1.7 and Netscape 6.x-7.x
 * - Netscape 4.8
 * - Opera 6 - Error object (and Presto) introduced in Opera 7
 * - Opera 7
 */

/************************************************************
 * JSON - public domain reference implementation by Douglas Crockford
 * @link http://www.JSON.org/json2.js
 ************************************************************/
/*jslint evil: true, regexp: false, bitwise: true */
/*global JSON2 */
/*members "", "\b", "\t", "\n", "\f", "\r", "\"", JSON2, "\\", apply,
    call, charCodeAt, getUTCDate, getUTCFullYear, getUTCHours,
    getUTCMinutes, getUTCMonth, getUTCSeconds, hasOwnProperty, join,
    lastIndex, length, parse, prototype, push, replace, slice, stringify,
    test, toJSON, toString, valueOf,
    objectToJSON
*/

// Create a JSON object only if one does not already exist. We create the
// methods in a closure to avoid creating global variables.

if (!this.JSON2) {
	this.JSON2 = {};
}

(function () {
    "use strict";

    function f(n) {
        // Format integers to have at least two digits.
        return n < 10 ? '0' + n : n;
    }

    function objectToJSON(value, key) {
        var objectType = Object.prototype.toString.apply(value);

        if (objectType === '[object Date]') {
            return isFinite(value.valueOf()) ?
	                value.getUTCFullYear()     + '-' +
	                f(value.getUTCMonth() + 1) + '-' +
	                f(value.getUTCDate())      + 'T' +
	                f(value.getUTCHours())     + ':' +
	                f(value.getUTCMinutes())   + ':' +
	                f(value.getUTCSeconds())   + 'Z' : null;
        }

        if (objectType === '[object String]' ||
                objectType === '[object Number]' ||
                objectType === '[object Boolean]') {
            return value.valueOf();
        }

        if (objectType !== '[object Array]' &&
                typeof value.toJSON === 'function') {
            return value.toJSON(key);
        }

        return value;
    }

    var cx = new RegExp('[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]', 'g'),
	// hack: workaround Snort false positive (sid 8443)
        pattern = '\\\\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]',
        escapable = new RegExp('[' + pattern, 'g'),
        gap,
        indent,
        meta = {    // table of character substitutions
            '\b': '\\b',
            '\t': '\\t',
            '\n': '\\n',
            '\f': '\\f',
            '\r': '\\r',
            '"' : '\\"',
            '\\': '\\\\'
        },
        rep;

    function quote(string) {

// If the string contains no control characters, no quote characters, and no
// backslash characters, then we can safely slap some quotes around it.
// Otherwise we must also replace the offending characters with safe escape
// sequences.

        escapable.lastIndex = 0;
        return escapable.test(string) ? '"' + string.replace(escapable, function (a) {
            var c = meta[a];
            return typeof c === 'string' ? c :
	                '\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4);
        }) + '"' : '"' + string + '"';
    }

    function str(key, holder) {

// Produce a string from holder[key].

        var i,          // The loop counter.
            k,          // The member key.
            v,          // The member value.
            length,
            mind = gap,
            partial,
            value = holder[key];

// If the value has a toJSON method, call it to obtain a replacement value.

        if (value && typeof value === 'object') {
            value = objectToJSON(value, key);
        }

// If we were called with a replacer function, then call the replacer to
// obtain a replacement value.

        if (typeof rep === 'function') {
            value = rep.call(holder, key, value);
        }

// What happens next depends on the value's type.

        switch (typeof value) {
        case 'string':
            return quote(value);

        case 'number':

// JSON numbers must be finite. Encode non-finite numbers as null.

            return isFinite(value) ? String(value) : 'null';

        case 'boolean':
        case 'null':

// If the value is a boolean or null, convert it to a string. Note:
// typeof null does not produce 'null'. The case is included here in
// the remote chance that this gets fixed someday.

            return String(value);

// If the type is 'object', we might be dealing with an object or an array or
// null.

        case 'object':

// Due to a specification blunder in ECMAScript, typeof null is 'object',
// so watch out for that case.

            if (!value) {
                return 'null';
            }

// Make an array to hold the partial results of stringifying this object value.

            gap += indent;
            partial = [];

// Is the value an array?

            if (Object.prototype.toString.apply(value) === '[object Array]') {

// The value is an array. Stringify every element. Use null as a placeholder
// for non-JSON values.

                length = value.length;
                for (i = 0; i < length; i += 1) {
                    partial[i] = str(i, value) || 'null';
                }

// Join all of the elements together, separated with commas, and wrap them in
// brackets.

                v = partial.length === 0 ? '[]' : gap ?
                        '[\n' + gap + partial.join(',\n' + gap) + '\n' + mind + ']' :
                        '[' + partial.join(',') + ']';
                gap = mind;
                return v;
            }

// If the replacer is an array, use it to select the members to be stringified.

            if (rep && typeof rep === 'object') {
                length = rep.length;
                for (i = 0; i < length; i += 1) {
                    if (typeof rep[i] === 'string') {
                        k = rep[i];
                        v = str(k, value);
                        if (v) {
                            partial.push(quote(k) + (gap ? ': ' : ':') + v);
                        }
                    }
                }
            } else {

// Otherwise, iterate through all of the keys in the object.

                for (k in value) {
                    if (Object.prototype.hasOwnProperty.call(value, k)) {
                        v = str(k, value);
                        if (v) {
                            partial.push(quote(k) + (gap ? ': ' : ':') + v);
                        }
                    }
                }
            }

// Join all of the member texts together, separated with commas,
// and wrap them in braces.

            v = partial.length === 0 ? '{}' : gap ?
                    '{\n' + gap + partial.join(',\n' + gap) + '\n' + mind + '}' :
                    '{' + partial.join(',') + '}';
            gap = mind;
            return v;
        }
    }

// If the JSON object does not yet have a stringify method, give it one.

    if (typeof JSON2.stringify !== 'function') {
        JSON2.stringify = function (value, replacer, space) {

// The stringify method takes a value and an optional replacer, and an optional
// space parameter, and returns a JSON text. The replacer can be a function
// that can replace values, or an array of strings that will select the keys.
// A default replacer method can be provided. Use of the space parameter can
// produce text that is more easily readable.

            var i;
            gap = '';
            indent = '';

// If the space parameter is a number, make an indent string containing that
// many spaces.

            if (typeof space === 'number') {
                for (i = 0; i < space; i += 1) {
                    indent += ' ';
                }

// If the space parameter is a string, it will be used as the indent string.

            } else if (typeof space === 'string') {
                indent = space;
            }

// If there is a replacer, it must be a function or an array.
// Otherwise, throw an error.

            rep = replacer;
            if (replacer && typeof replacer !== 'function' &&
                    (typeof replacer !== 'object' ||
                    typeof replacer.length !== 'number')) {
                throw new Error('JSON.stringify');
            }

// Make a fake root object containing our value under the key of ''.
// Return the result of stringifying the value.

            return str('', {'': value});
        };
    }

// If the JSON object does not yet have a parse method, give it one.

    if (typeof JSON2.parse !== 'function') {
        JSON2.parse = function (text, reviver) {

// The parse method takes a text and an optional reviver function, and returns
// a JavaScript value if the text is a valid JSON text.

            var j;

            function walk(holder, key) {

// The walk method is used to recursively walk the resulting structure so
// that modifications can be made.

                var k, v, value = holder[key];
                if (value && typeof value === 'object') {
                    for (k in value) {
                        if (Object.prototype.hasOwnProperty.call(value, k)) {
                            v = walk(value, k);
                            if (v !== undefined) {
                                value[k] = v;
                            } else {
                                delete value[k];
                            }
                        }
                    }
                }
                return reviver.call(holder, key, value);
            }

// Parsing happens in four stages. In the first stage, we replace certain
// Unicode characters with escape sequences. JavaScript handles many characters
// incorrectly, either silently deleting them, or treating them as line endings.

            text = String(text);
            cx.lastIndex = 0;
            if (cx.test(text)) {
                text = text.replace(cx, function (a) {
                    return '\\u' +
                        ('0000' + a.charCodeAt(0).toString(16)).slice(-4);
                });
            }

// In the second stage, we run the text against regular expressions that look
// for non-JSON patterns. We are especially concerned with '()' and 'new'
// because they can cause invocation, and '=' because it can cause mutation.
// But just to be safe, we want to reject all unexpected forms.

// We split the second stage into 4 regexp operations in order to work around
// crippling inefficiencies in IE's and Safari's regexp engines. First we
// replace the JSON backslash pairs with '@' (a non-JSON character). Second, we
// replace all simple value tokens with ']' characters. Third, we delete all
// open brackets that follow a colon or comma or that begin the text. Finally,
// we look to see that the remaining characters are only whitespace or ']' or
// ',' or ':' or '{' or '}'. If that is so, then the text is safe for eval.

            if ((new RegExp('^[\\],:{}\\s]*$'))
                    .test(text.replace(new RegExp('\\\\(?:["\\\\/bfnrt]|u[0-9a-fA-F]{4})', 'g'), '@')
                        .replace(new RegExp('"[^"\\\\\n\r]*"|true|false|null|-?\\d+(?:\\.\\d*)?(?:[eE][+\\-]?\\d+)?', 'g'), ']')
                        .replace(new RegExp('(?:^|:|,)(?:\\s*\\[)+', 'g'), ''))) {

// In the third stage we use the eval function to compile the text into a
// JavaScript structure. The '{' operator is subject to a syntactic ambiguity
// in JavaScript: it can begin a block or an object literal. We wrap the text
// in parens to eliminate the ambiguity.

                j = eval('(' + text + ')');

// In the optional fourth stage, we recursively walk the new structure, passing
// each name/value pair to a reviver function for possible transformation.

                return typeof reviver === 'function' ?
	                    walk({'': j}, '') : j;
            }

// If the text is not JSON parseable, then a SyntaxError is thrown.

            throw new SyntaxError('JSON.parse');
        };
    }
}());
/************************************************************
 * end JSON
 ************************************************************/

/*jslint browser:true, plusplus:true, vars:true, nomen:true, evil:true */
/*global window */
/*global unescape */
/*global ActiveXObject */
/*global _snaq:true */
/*members encodeURIComponent, decodeURIComponent, getElementsByTagName,
	shift, unshift,
	addEventListener, attachEvent, removeEventListener, detachEvent,
	cookie, domain, readyState, documentElement, doScroll, title, text,
	location, top, document, referrer, parent, links, href, protocol, GearsFactory,
	event, which, button, srcElement, type, target,
	parentNode, tagName, hostname, className,
	userAgent, cookieEnabled, platform, mimeTypes, enabledPlugin, javaEnabled,
	XDomainRequest, XMLHttpRequest, ActiveXObject, open, setRequestHeader, onreadystatechange, setRequestHeader, send, readyState, status,
	getTime, getTimeAlias, setTime, toGMTString, getHours, getMinutes, getSeconds,
	toLowerCase, charAt, indexOf, lastIndexOf, split, slice, toUpperCase,
	onload, src,
	round, random,
	exec,
	res, width, height,
	pdf, qt, realp, wma, dir, fla, java, gears, ag,
	hook, getHook, getVisitorId, getVisitorInfo, setTrackerUrl, setAccount, setSiteId,
	setDownloadExtensions, addDownloadExtensions,
	setDomains, setIgnoreClasses, setRequestMethod,
	setReferrerUrl, setCustomUrl, setDocumentTitle,
	setDownloadClasses, setLinkClasses,
	discardHashTag,
	setCookieNamePrefix, setCookieDomain, setCookiePath, setVisitorIdCookie,
	setVisitorCookieTimeout, setSessionCookieTimeout, setReferralCookieTimeout,
	doNotTrack, setDoNotTrack, msDoNotTrack,
	addListener, enableLinkTracking, setLinkTrackingTimer,
	setHeartBeatTimer, killFrame, redirectFile, setCountPreRendered,
	trackEvent, trackLink, trackPageView, trackImpression,
	addPlugin, getAccount, getTracker, getAsyncTracker
*/
var
	// asynchronous tracker (or proxy)
	_snaq = _snaq || [],

	// SnowPlow singleton and namespace
	SnowPlow = SnowPlow || (function () {
		"use strict";

		/************************************************************
		 * Private data
		 ************************************************************/

		var expireDateTime,

			/* plugins */
			plugins = {},

			/* alias frequently used globals for added minification */
			documentAlias = document,
			navigatorAlias = navigator,
			screenAlias = screen,
			windowAlias = window,

			/* DOM Ready */
			hasLoaded = false,
			registeredOnLoadHandlers = [],

			/* encode */
			encodeWrapper = windowAlias.encodeURIComponent,

			/* decode */
			decodeWrapper = windowAlias.decodeURIComponent,

			/* urldecode */
			urldecode = unescape,

			/* asynchronous tracker */
			asyncTracker,

			/* iterator */
			i;

		/************************************************************
		 * Private methods
		 ************************************************************/

		/*
		 * Is property defined?
		 */
		function isDefined(property) {
			return typeof property !== 'undefined';
		}

		/*
		 * Is property a function?
		 */
		function isFunction(property) {
			return typeof property === 'function';
		}

		/*
		 * Is property an object?
		 *
		 * @return bool Returns true if property is null, an Object, or subclass of Object (i.e., an instanceof String, Date, etc.)
		 */
		function isObject(property) {
			return typeof property === 'object';
		}

		/*
		 * Is property a string?
		 */
		function isString(property) {
			return typeof property === 'string' || property instanceof String;
		}

		/*
		 * apply wrapper
		 *
		 * @param array parameterArray An array comprising either:
		 *      [ 'methodName', optional_parameters ]
		 * or:
		 *      [ functionObject, optional_parameters ]
		 */
		function apply() {
			var i, f, parameterArray;

			for (i = 0; i < arguments.length; i += 1) {
				parameterArray = arguments[i];
				f = parameterArray.shift();

				if (isString(f)) {
					asyncTracker[f].apply(asyncTracker, parameterArray);
				} else {
					f.apply(asyncTracker, parameterArray);
				}
			}
		}

		/*
		 * Cross-browser helper function to add event handler
		 */
		function addEventListener(element, eventType, eventHandler, useCapture) {
			if (element.addEventListener) {
				element.addEventListener(eventType, eventHandler, useCapture);
				return true;
			}
			if (element.attachEvent) {
				return element.attachEvent('on' + eventType, eventHandler);
			}
			element['on' + eventType] = eventHandler;
		}

		/*
		 * Call plugin hook methods
		 */
		function executePluginMethod(methodName, callback) {
			var result = '',
				i,
				pluginMethod;

			for (i in plugins) {
				if (Object.prototype.hasOwnProperty.call(plugins, i)) {
					pluginMethod = plugins[i][methodName];
					if (isFunction(pluginMethod)) {
						result += pluginMethod(callback);
					}
				}
			}

			return result;
		}

		/*
		 * Handle beforeunload event
		 *
		 * Subject to Safari's "Runaway JavaScript Timer" and
		 * Chrome V8 extension that terminates JS that exhibits
		 * "slow unload", i.e., calling getTime() > 1000 times
		 */
		function beforeUnloadHandler() {
			var now;

			executePluginMethod('unload');

			/*
			 * Delay/pause (blocks UI)
			 */
			if (expireDateTime) {
				// the things we do for backwards compatibility...
				// in ECMA-262 5th ed., we could simply use:
				//     while (Date.now() < expireDateTime) { }
				do {
					now = new Date();
				} while (now.getTimeAlias() < expireDateTime);
			}
		}

		/*
		 * Handler for onload event
		 */
		function loadHandler() {
			var i;

			if (!hasLoaded) {
				hasLoaded = true;
				executePluginMethod('load');
				for (i = 0; i < registeredOnLoadHandlers.length; i++) {
					registeredOnLoadHandlers[i]();
				}
			}
			return true;
		}

		/*
		 * Add onload or DOM ready handler
		 */
		function addReadyListener() {
			var _timer;

			if (documentAlias.addEventListener) {
				addEventListener(documentAlias, 'DOMContentLoaded', function ready() {
					documentAlias.removeEventListener('DOMContentLoaded', ready, false);
					loadHandler();
				});
			} else if (documentAlias.attachEvent) {
				documentAlias.attachEvent('onreadystatechange', function ready() {
					if (documentAlias.readyState === 'complete') {
						documentAlias.detachEvent('onreadystatechange', ready);
						loadHandler();
					}
				});

				if (documentAlias.documentElement.doScroll && windowAlias === windowAlias.top) {
					(function ready() {
						if (!hasLoaded) {
							try {
								documentAlias.documentElement.doScroll('left');
							} catch (error) {
								setTimeout(ready, 0);
								return;
							}
							loadHandler();
						}
					}());
				}
			}

			// sniff for older WebKit versions
			if ((new RegExp('WebKit')).test(navigatorAlias.userAgent)) {
				_timer = setInterval(function () {
					if (hasLoaded || /loaded|complete/.test(documentAlias.readyState)) {
						clearInterval(_timer);
						loadHandler();
					}
				}, 10);
			}

			// fallback
			addEventListener(windowAlias, 'load', loadHandler, false);
		}

		/*
		 * Get page referrer
		 */
		function getReferrer() {
			var referrer = '';

			try {
				referrer = windowAlias.top.document.referrer;
			} catch (e) {
				if (windowAlias.parent) {
					try {
						referrer = windowAlias.parent.document.referrer;
					} catch (e2) {
						referrer = '';
					}
				}
			}
			if (referrer === '') {
				referrer = documentAlias.referrer;
			}

			return referrer;
		}

		/*
		 * Extract scheme/protocol from URL
		 */
		function getProtocolScheme(url) {
			var e = new RegExp('^([a-z]+):'),
				matches = e.exec(url);

			return matches ? matches[1] : null;
		}

		/*
		 * Extract hostname from URL
		 */
		function getHostName(url) {
			// scheme : // [username [: password] @] hostame [: port] [/ [path] [? query] [# fragment]]
			var e = new RegExp('^(?:(?:https?|ftp):)/*(?:[^@]+@)?([^:/#]+)'),
				matches = e.exec(url);

			return matches ? matches[1] : url;
		}

		/*
		 * Extract parameter from URL
		 */
		function getParameter(url, name) {
			// scheme : // [username [: password] @] hostame [: port] [/ [path] [? query] [# fragment]]
			var e = new RegExp('^(?:https?|ftp)(?::/*(?:[^?]+)[?])([^#]+)'),
				matches = e.exec(url),
				f = new RegExp('(?:^|&)' + name + '=([^&]*)'),
				result = matches ? f.exec(matches[1]) : 0;

			return result ? decodeWrapper(result[1]) : '';
		}

		/*
		 * Set cookie value
		 */
		function setCookie(cookieName, value, msToExpire, path, domain, secure) {
			var expiryDate;

			// relative time to expire in milliseconds
			if (msToExpire) {
				expiryDate = new Date();
				expiryDate.setTime(expiryDate.getTime() + msToExpire);
			}

			documentAlias.cookie = cookieName + '=' + encodeWrapper(value) +
				(msToExpire ? ';expires=' + expiryDate.toGMTString() : '') +
				';path=' + (path || '/') +
				(domain ? ';domain=' + domain : '') +
				(secure ? ';secure' : '');
		}

		/*
		 * Get cookie value
		 */
		function getCookie(cookieName) {
			var cookiePattern = new RegExp('(^|;)[ ]*' + cookieName + '=([^;]*)'),

				cookieMatch = cookiePattern.exec(documentAlias.cookie);

			return cookieMatch ? decodeWrapper(cookieMatch[2]) : 0;
		}

		/*
		 * UTF-8 encoding
		 */
		function utf8_encode(argString) {
			return urldecode(encodeWrapper(argString));
		}

		/************************************************************
		 * sha1
		 * - based on sha1 from http://phpjs.org/functions/sha1:512 (MIT / GPL v2)
		 ************************************************************/
		function sha1(str) {
			// +   original by: Webtoolkit.info (http://www.webtoolkit.info/)
			// + namespaced by: Michael White (http://getsprink.com)
			// +      input by: Brett Zamir (http://brett-zamir.me)
			// +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
			// +   jslinted by: Anthon Pang (http://piwik.org)

			var
				rotate_left = function (n, s) {
					return (n << s) | (n >>> (32 - s));
				},

				cvt_hex = function (val) {
					var str = '',
						i,
						v;

					for (i = 7; i >= 0; i--) {
						v = (val >>> (i * 4)) & 0x0f;
						str += v.toString(16);
					}
					return str;
				},

				blockstart,
				i,
				j,
				W = [],
				H0 = 0x67452301,
				H1 = 0xEFCDAB89,
				H2 = 0x98BADCFE,
				H3 = 0x10325476,
				H4 = 0xC3D2E1F0,
				A,
				B,
				C,
				D,
				E,
				temp,
				str_len,
				word_array = [];

			str = utf8_encode(str);
			str_len = str.length;

			for (i = 0; i < str_len - 3; i += 4) {
				j = str.charCodeAt(i) << 24 | str.charCodeAt(i + 1) << 16 |
					str.charCodeAt(i + 2) << 8 | str.charCodeAt(i + 3);
				word_array.push(j);
			}

			switch (str_len & 3) {
			case 0:
				i = 0x080000000;
				break;
			case 1:
				i = str.charCodeAt(str_len - 1) << 24 | 0x0800000;
				break;
			case 2:
				i = str.charCodeAt(str_len - 2) << 24 | str.charCodeAt(str_len - 1) << 16 | 0x08000;
				break;
			case 3:
				i = str.charCodeAt(str_len - 3) << 24 | str.charCodeAt(str_len - 2) << 16 | str.charCodeAt(str_len - 1) << 8 | 0x80;
				break;
			}

			word_array.push(i);

			while ((word_array.length & 15) !== 14) {
				word_array.push(0);
			}

			word_array.push(str_len >>> 29);
			word_array.push((str_len << 3) & 0x0ffffffff);

			for (blockstart = 0; blockstart < word_array.length; blockstart += 16) {
				for (i = 0; i < 16; i++) {
					W[i] = word_array[blockstart + i];
				}

				for (i = 16; i <= 79; i++) {
					W[i] = rotate_left(W[i - 3] ^ W[i - 8] ^ W[i - 14] ^ W[i - 16], 1);
				}

				A = H0;
				B = H1;
				C = H2;
				D = H3;
				E = H4;

				for (i = 0; i <= 19; i++) {
					temp = (rotate_left(A, 5) + ((B & C) | (~B & D)) + E + W[i] + 0x5A827999) & 0x0ffffffff;
					E = D;
					D = C;
					C = rotate_left(B, 30);
					B = A;
					A = temp;
				}

				for (i = 20; i <= 39; i++) {
					temp = (rotate_left(A, 5) + (B ^ C ^ D) + E + W[i] + 0x6ED9EBA1) & 0x0ffffffff;
					E = D;
					D = C;
					C = rotate_left(B, 30);
					B = A;
					A = temp;
				}

				for (i = 40; i <= 59; i++) {
					temp = (rotate_left(A, 5) + ((B & C) | (B & D) | (C & D)) + E + W[i] + 0x8F1BBCDC) & 0x0ffffffff;
					E = D;
					D = C;
					C = rotate_left(B, 30);
					B = A;
					A = temp;
				}

				for (i = 60; i <= 79; i++) {
					temp = (rotate_left(A, 5) + (B ^ C ^ D) + E + W[i] + 0xCA62C1D6) & 0x0ffffffff;
					E = D;
					D = C;
					C = rotate_left(B, 30);
					B = A;
					A = temp;
				}

				H0 = (H0 + A) & 0x0ffffffff;
				H1 = (H1 + B) & 0x0ffffffff;
				H2 = (H2 + C) & 0x0ffffffff;
				H3 = (H3 + D) & 0x0ffffffff;
				H4 = (H4 + E) & 0x0ffffffff;
			}

			temp = cvt_hex(H0) + cvt_hex(H1) + cvt_hex(H2) + cvt_hex(H3) + cvt_hex(H4);
			return temp.toLowerCase();
		}
		/************************************************************
		 * end sha1
		 ************************************************************/

		/*
		 * Fix-up URL when page rendered from search engine cache or translated page.
         * TODO: Eurgh, we should move this to a referrer-cleaning post-process step
		 */
		function urlFixup(hostName, href, referrer) {
			if (hostName === 'translate.googleusercontent.com') {		// Google
				if (referrer === '') {
					referrer = href;
				}
				href = getParameter(href, 'u');
				hostName = getHostName(href);
			} else if (hostName === 'cc.bingj.com' ||					// Bing
					hostName === 'webcache.googleusercontent.com' ||	// Google
					hostName.slice(0, 5) === '74.6.') {					// Yahoo (via Inktomi 74.6.0.0/16)
				href = documentAlias.links[0].href;
				hostName = getHostName(href);
			}
			return [hostName, href, referrer];
		}

		/*
		 * Fix-up domain
		 */
		function domainFixup(domain) {
			var dl = domain.length;

			// remove trailing '.'
			if (domain.charAt(--dl) === '.') {
				domain = domain.slice(0, dl);
			}
			// remove leading '*'
			if (domain.slice(0, 2) === '*.') {
				domain = domain.slice(1);
			}
			return domain;
		}

		/*
		 * Title fixup
		 */
		function titleFixup(title) {
			if (!isString(title)) {
				title = title.text || '';

				var tmp = documentAlias.getElementsByTagName('title');
				if (tmp && isDefined(tmp[0])) {
					title = tmp[0].text;
				}
			}
			return title;
		}

		/*
		 * Piwik Tracker class
		 *
		 * trackerUrl and trackerSiteId are optional arguments to the constructor
		 *
		 * See: Tracker.setTrackerUrl() and Tracker.setSiteId()
		 */
		function Tracker(accountId) {

			/************************************************************
			 * Private members
			 ************************************************************/

			var
/*<DEBUG>*/
				/*
				 * registered test hooks
				 */
				registeredHooks = {},
/*</DEBUG>*/

				// Current URL and Referrer URL
				locationArray = urlFixup(documentAlias.domain, windowAlias.location.href, getReferrer()),
				domainAlias = domainFixup(locationArray[0]),
				locationHrefAlias = locationArray[1],
				configReferrerUrl = locationArray[2],

				// Request method is always GET for SnowPlow
				configRequestMethod = 'GET',

				// Tracker URL
				configTrackerUrl = trackerUrlFromAccountId(accountId), // Updated for SnowPlow

				// Site ID
				configTrackerSiteId = '', // Updated for SnowPlow. Starting long road to full removal

				// Document URL
				configCustomUrl,

				// Document title
				configTitle = documentAlias.title,

				// Extensions to be treated as download links
				configDownloadExtensions = '7z|aac|ar[cj]|as[fx]|avi|bin|csv|deb|dmg|doc|exe|flv|gif|gz|gzip|hqx|jar|jpe?g|js|mp(2|3|4|e?g)|mov(ie)?|ms[ip]|od[bfgpst]|og[gv]|pdf|phps|png|ppt|qtm?|ra[mr]?|rpm|sea|sit|tar|t?bz2?|tgz|torrent|txt|wav|wm[av]|wpd||xls|xml|z|zip',

				// Hosts or alias(es) to not treat as outlinks
				configHostsAlias = [domainAlias],

				// HTML anchor element classes to not track
				configIgnoreClasses = [],

				// HTML anchor element classes to treat as downloads
				configDownloadClasses = [],

				// HTML anchor element classes to treat at outlinks
				configLinkClasses = [],

				// Maximum delay to wait for web bug image to be fetched (in milliseconds)
				configTrackerPause = 500,

				// Minimum visit time after initial page view (in milliseconds)
				configMinimumVisitTime,

				// Recurring heart beat after initial ping (in milliseconds)
				configHeartBeatTimer,

				// Disallow hash tags in URL
				configDiscardHashTag,

				// First-party cookie name prefix
				configCookieNamePrefix = '_sp_',

				// First-party cookie domain
				// User agent defaults to origin hostname
				configCookieDomain,

				// First-party cookie path
				// Default is user agent defined.
				configCookiePath,

				// Do Not Track
				configDoNotTrack,

				// Count sites which are pre-rendered
				configCountPreRendered,

				// Life of the visitor cookie (in milliseconds)
				configVisitorCookieTimeout = 63072000000, // 2 years

				// Life of the session cookie (in milliseconds)
				configSessionCookieTimeout = 1800000, // 30 minutes

				// Life of the referral cookie (in milliseconds)
				configReferralCookieTimeout = 15768000000, // 6 months

                // Browser language (or Windows language for IE). Imperfect but CloudFront doesn't log the Accept-Language header
                configBrowserLanguage = window.navigator.userLanguage || window.navigator.language,

				// Should cookies have the secure flag set
				cookieSecure = documentAlias.location.protocol === 'https',

				// Browser features via client-side data collection
				browserFeatures = {},

				// Guard against installing the link tracker more than once per Tracker instance
				linkTrackingInstalled = false,

				// Guard against installing the activity tracker more than once per Tracker instance
				activityTrackingInstalled = false,

				// Last activity timestamp
				lastActivityTime,

				// Internal state of the pseudo click handler
				lastButton,
				lastTarget,

				// Hash function
				hash = sha1,

				// Domain hash value
				domainHash,

				// Visitor UUID
				visitorUUID;

			/*
			 * Removes hash tag from the URL
			 *
			 * URLs are purified before being recorded in the cookie,
			 * or before being sent as GET parameters
			 */
			function purify(url) {
				var targetPattern;

				if (configDiscardHashTag) {
					targetPattern = new RegExp('#.*');
					return url.replace(targetPattern, '');
				}
				return url;
			}

			/*
			 * Resolve relative reference
			 *
			 * Note: not as described in rfc3986 section 5.2
			 */
			function resolveRelativeReference(baseUrl, url) {
				var protocol = getProtocolScheme(url),
					i;

				if (protocol) {
					return url;
				}

				if (url.slice(0, 1) === '/') {
					return getProtocolScheme(baseUrl) + '://' + getHostName(baseUrl) + url;
				}

				baseUrl = purify(baseUrl);
				if ((i = baseUrl.indexOf('?')) >= 0) {
					baseUrl = baseUrl.slice(0, i);
				}
				if ((i = baseUrl.lastIndexOf('/')) !== baseUrl.length - 1) {
					baseUrl = baseUrl.slice(0, i + 1);
				}

				return baseUrl + url;
			}

			/*
			 * Is the host local? (i.e., not an outlink)
			 */
			function isSiteHostName(hostName) {
				var i,
					alias,
					offset;

				for (i = 0; i < configHostsAlias.length; i++) {
					alias = domainFixup(configHostsAlias[i].toLowerCase());

					if (hostName === alias) {
						return true;
					}

					if (alias.slice(0, 1) === '.') {
						if (hostName === alias.slice(1)) {
							return true;
						}

						offset = hostName.length - alias.length;
						if ((offset > 0) && (hostName.slice(offset) === alias)) {
							return true;
						}
					}
				}
				return false;
			}

			/*
			 * Send image request to Piwik server using GET.
			 * A web bug/beacon is a transparent, single pixel (1x1) image
			 */
			function getImage(request) {
				var image = new Image(1, 1);

				image.onload = function () { };
				image.src = configTrackerUrl + (configTrackerUrl.indexOf('?') < 0 ? '?' : '&') + request;
			}

			/*
			 * Send request
			 */
			function sendRequest(request, delay) {
				var now = new Date();

				if (!configDoNotTrack) {
					getImage(request);
					expireDateTime = now.getTime() + delay;
				}
			}

			/*
			 * Get cookie name with prefix and domain hash
			 */
			function getCookieName(baseName) {
				// NOTE: If the cookie name is changed, we must also update the PiwikTracker.php which
				// will attempt to discover first party cookies. eg. See the PHP Client method getVisitorId()
				return configCookieNamePrefix + baseName + '.' + configTrackerSiteId + '.' + domainHash;
			}

			/*
			 * Does browser have cookies enabled (for this site)?
			 */
			function hasCookies() {
				var testCookieName = getCookieName('testcookie');

				if (!isDefined(navigatorAlias.cookieEnabled)) {
					setCookie(testCookieName, '1');
					return getCookie(testCookieName) === '1' ? '1' : '0';
				}

				return navigatorAlias.cookieEnabled ? '1' : '0';
			}

			/*
			 * Update domain hash
			 */
			function updateDomainHash() {
				domainHash = hash((configCookieDomain || domainAlias) + (configCookiePath || '/')).slice(0, 4); // 4 hexits = 16 bits
			}

			/*
			 * Process all "activity" events.
			 * For performance, this function must have low overhead.
			 */
			function activityHandler() {
				var now = new Date();

				lastActivityTime = now.getTime();
			}

			/*
			 * Sets the Visitor ID cookie: either the first time loadVisitorIdCookie is called
			 * or when there is a new visit or a new page view
			 */
			function setVisitorIdCookie(uuid, createTs, visitCount, nowTs, lastVisitTs) {
				setCookie(getCookieName('id'), uuid + '.' + createTs + '.' + visitCount + '.' + nowTs + '.' + lastVisitTs, configVisitorCookieTimeout, configCookiePath, configCookieDomain, cookieSecure);
			}

			/*
			 * Load visitor ID cookie
			 */
			function loadVisitorIdCookie() {
				var now = new Date(),
					nowTs = Math.round(now.getTime() / 1000),
					id = getCookie(getCookieName('id')),
					tmpContainer;

				if (id) {
					tmpContainer = id.split('.');

					// New visitor set to 0 now
					tmpContainer.unshift('0');
				} else {
					// uuid - generate a pseudo-unique ID to fingerprint this user;
					// Note: this isn't a RFC4122-compliant UUID
					if (!visitorUUID) {
						visitorUUID = hash(
							(navigatorAlias.userAgent || '') +
								(navigatorAlias.platform || '') +
								JSON2.stringify(browserFeatures) + nowTs
						).slice(0, 16); // 16 hexits = 64 bits
					}

					tmpContainer = [
						// new visitor
						'1',

						// uuid
						visitorUUID,

						// creation timestamp - seconds since Unix epoch
						nowTs,

						// visitCount - 0 = no previous visit
						0,

						// current visit timestamp
						nowTs,

						// last visit timestamp - blank meaning no previous visit
						''
					];
				}
				return tmpContainer;
			}

			/*
			 * Returns the URL to call piwik.php,
			 * with the standard parameters (plugins, resolution, url, referrer, etc.).
			 * Sends the pageview and browser settings with every request in case of race conditions.
			 */
			function getRequest(request, pluginMethod) {
				var i,
					now = new Date(),
					nowTs = Math.round(now.getTime() / 1000),
					newVisitor,
					uuid,
					visitCount,
					createTs,
					currentVisitTs,
					lastVisitTs,
					referralTs,
					referralUrl,
					referralUrlMaxLength = 1024,
					currentReferrerHostName,
					originalReferrerHostName,
					idname = getCookieName('id'),
					sesname = getCookieName('ses'),
					id = loadVisitorIdCookie(),
					ses = getCookie(sesname),
					currentUrl = configCustomUrl || locationHrefAlias,
                    featurePrefix;

				if (configDoNotTrack) {
					setCookie(idname, '', -1, configCookiePath, configCookieDomain);
					setCookie(sesname, '', -1, configCookiePath, configCookieDomain);
					return '';
				}

				newVisitor = id[0];
				uuid = id[1];
				createTs = id[2];
				visitCount = id[3];
				currentVisitTs = id[4];
				lastVisitTs = id[5];

                // New session
				if (!ses) {
					// New session (aka new visit)
					visitCount++;

                    // Update the last visit timestamp
					lastVisitTs = currentVisitTs;
				}

/*<SNOWPLOW> Updated behaviour */

				// Build out the rest of the request
				request += 
					'&tid=' + String(Math.random()).slice(2, 8) +
					'&uid=' + uuid +
                    '&vid=' + visitCount +
                    '&lang=' + configBrowserLanguage +
                    (configReferrerUrl.length ? '&refr=' + encodeWrapper(purify(configReferrerUrl)) : '');

				// Browser features. Cookie and resolution don't get prepended with f_ (because they're not optional features)
				for (i in browserFeatures) {
					if (Object.prototype.hasOwnProperty.call(browserFeatures, i)) {
						featurePrefix = (i === 'res' || i === 'cookie') ? '&' : '&f_';
                        request += featurePrefix + i + '=' + browserFeatures[i];
					}
				}

                // Finally add the page URL
                request += '&url=' + encodeWrapper(purify(window.location));

/*</SNOWPLOW>*/
				// Update cookies
				setVisitorIdCookie(uuid, createTs, visitCount, nowTs, lastVisitTs);
				setCookie(sesname, '*', configSessionCookieTimeout, configCookiePath, configCookieDomain, cookieSecure);

				// Tracker plugin hook
				request += executePluginMethod(pluginMethod);

				return request;
			}

/*<SNOWPLOW> New SnowPlow functionality */

            /**
             * Builds a tracker URL from an account ID.
             * The trick here is that each account ID is in fact the subdomain on a specific Amazon CloudFront URL.
             * We don't bother to support custom CNAMEs because Amazon CloudFront doesn't support that for SSL.
             *
             * @param string account The account ID to build the tracker URL from
             *
             * @return string trackerUrl The tracker URL
             */
            function trackerUrlFromAccountId(accountId) {
                return ('https:' == document.location.protocol ? 'https' : 'http') + '://' + accountId + '.cloudfront.net/ice.png';
            }

            /**
             * Log an event happening on this page
             *
             * @param string category The name you supply for the group of objects you want to track
             * @param string action A string that is uniquely paired with each category, and commonly used to define the type of user interaction for the web object
             * @param string label (optional) An optional string to provide additional dimensions to the event data
             * @param int|float|string value (optional) An integer that you can use to provide numerical data about the user event
             */
            function logEvent(category, action, label, property, value) {

                // All events have a category and an action
                var request =
                    '&ev_ca=' + encodeWrapper(category)
                    + '&ev_ac=' + encodeWrapper(action);

                // Label, property and value are optional
                if (String(label).length) {
                    request += '&ev_la=' + encodeWrapper(label);
                }
                if (String(property).length) {
                    request += '&ev_pr=' + encodeWrapper(property);
                }
                if (String(value).length) {
                    request += '&ev_va=' + encodeWrapper(value);
                }

                request = getRequest(request, 'event');
                sendRequest(request, configTrackerPause);
            }

            /**
             * Log an ad impression
             *
             * @param string bannerId Identifier for the ad banner displayed
             * @param string campaignId (optional) Identifier for the campaign which the banner belongs to
             * @param string advertiserId (optional) Identifier for the advertiser which the campaign belongs to
             * @param string userId (optional) Ad server identifier for the viewer of the banner
             */
            function logImpression(bannerId, campaignId, advertiserId, userId) {
                var request = '';

                // All events have a banner ID
                request += '&ad_ba=' + encodeWrapper(bannerId);

                // Campaign, advertiser and user IDs are optional
                if (String(campaignId).length) {
                    request += '&ad_ca=' + encodeWrapper(campaignId);
                }
                if (String(advertiserId).length) {
                    request += '&ad_ad=' + encodeWrapper(advertiserId);
                }
                if (String(userId).length) {
                    request += '&ad_uid=' + encodeWrapper(userId);
                }

                request = getRequest(request, configCustomData, 'adimp');
                sendRequest(request, configTrackerPause);
            }

/*</SNOWPLOW>*/

			/*
			 * Log the page view / visit
			 */
			function logPageView(customTitle) {
				var now = new Date(),
					request = getRequest('page=' + encodeWrapper(titleFixup(customTitle || configTitle)), 'log');

				sendRequest(request, configTrackerPause);

				// send ping
				if (configMinimumVisitTime && configHeartBeatTimer && !activityTrackingInstalled) {
					activityTrackingInstalled = true;

					// add event handlers; cross-browser compatibility here varies significantly
					// @see http://quirksmode.org/dom/events
					addEventListener(documentAlias, 'click', activityHandler);
					addEventListener(documentAlias, 'mouseup', activityHandler);
					addEventListener(documentAlias, 'mousedown', activityHandler);
					addEventListener(documentAlias, 'mousemove', activityHandler);
					addEventListener(documentAlias, 'mousewheel', activityHandler);
					addEventListener(windowAlias, 'DOMMouseScroll', activityHandler);
					addEventListener(windowAlias, 'scroll', activityHandler);
					addEventListener(documentAlias, 'keypress', activityHandler);
					addEventListener(documentAlias, 'keydown', activityHandler);
					addEventListener(documentAlias, 'keyup', activityHandler);
					addEventListener(windowAlias, 'resize', activityHandler);
					addEventListener(windowAlias, 'focus', activityHandler);
					addEventListener(windowAlias, 'blur', activityHandler);

					// periodic check for activity
					lastActivityTime = now.getTime();
					setTimeout(function heartBeat() {
						var now = new Date(),
							request;

						// There was activity during the heart beat period;
						// on average, this is going to overstate the visitDuration by configHeartBeatTimer/2
						if ((lastActivityTime + configHeartBeatTimer) > now.getTime()) {
							// send ping if minimum visit time has elapsed
							if (configMinimumVisitTime < now.getTime()) {
								request = getRequest('ping=1', 'ping');

								sendRequest(request, configTrackerPause);
							}

							// resume heart beat
							setTimeout(heartBeat, configHeartBeatTimer);
						}
						// Else heart beat cancelled due to inactivity
					}, configHeartBeatTimer);
				}
			}

			/*
			 * Log the link or click with the server
			 */
			function logLink(url, linkType) {
				var request = getRequest(linkType + '=' + encodeWrapper(purify(url)), 'link');

				sendRequest(request, configTrackerPause);
			}

			/*
			 * Browser prefix
			 */
			function prefixPropertyName(prefix, propertyName) {
				
                if (prefix !== '') {
					return prefix + propertyName.charAt(0).toUpperCase() + propertyName.slice(1);
				}

				return propertyName;
			}

			/*
			 * Check for pre-rendered web pages, and log the page view/link
			 * according to the configuration and/or visibility
			 *
			 * @see http://dvcs.w3.org/hg/webperf/raw-file/tip/specs/PageVisibility/Overview.html
			 */
			function trackCallback(callback) {
				var isPreRendered,
					i,
					// Chrome 13, IE10, FF10
					prefixes = ['', 'webkit', 'ms', 'moz'],
					prefix;

				if (!configCountPreRendered) {
					for (i = 0; i < prefixes.length; i++) {
						prefix = prefixes[i];

						// does this browser support the page visibility API?
						if (Object.prototype.hasOwnProperty.call(documentAlias, prefixPropertyName(prefix, 'hidden'))) {
							// if pre-rendered, then defer callback until page visibility changes
							if (documentAlias[prefixPropertyName(prefix, 'visibilityState')] === 'prerender') {
								isPreRendered = true;
							}
							break;
						}
					}
				}

				if (isPreRendered) {
					// note: the event name doesn't follow the same naming convention as vendor properties
					addEventListener(documentAlias, prefix + 'visibilitychange', function ready() {
						documentAlias.removeEventListener(prefix + 'visibilitychange', ready, false);
						callback();
					});
					return;
				}

				// configCountPreRendered === true || isPreRendered === false
				callback();
			}

			/*
			 * Construct regular expression of classes
			 */
			function getClassesRegExp(configClasses, defaultClass) {
				var i,
					classesRegExp = '(^| )(piwik[_-]' + defaultClass;

				if (configClasses) {
					for (i = 0; i < configClasses.length; i++) {
						classesRegExp += '|' + configClasses[i];
					}
				}
				classesRegExp += ')( |$)';

				return new RegExp(classesRegExp);
			}

			/*
			 * Link or Download?
			 */
			function getLinkType(className, href, isInLink) {
				// outlinks
				if (!isInLink) {
					return 'link';
				}

				// does class indicate whether it is an (explicit/forced) outlink or a download?
				var downloadPattern = getClassesRegExp(configDownloadClasses, 'download'),
					linkPattern = getClassesRegExp(configLinkClasses, 'link'),

					// does file extension indicate that it is a download?
					downloadExtensionsPattern = new RegExp('\\.(' + configDownloadExtensions + ')([?&#]|$)', 'i');

				// optimization of the if..elseif..else construct below
				return linkPattern.test(className) ? 'link' : (downloadPattern.test(className) || downloadExtensionsPattern.test(href) ? 'download' : 0);
			}

			/*
			 * Process clicks
			 */
			function processClick(sourceElement) {
				var parentElement,
					tag,
					linkType;

				while ((parentElement = sourceElement.parentNode) !== null &&
						isDefined(parentElement) && // buggy IE5.5
						((tag = sourceElement.tagName.toUpperCase()) !== 'A' && tag !== 'AREA')) {
					sourceElement = parentElement;
				}

				if (isDefined(sourceElement.href)) {
					// browsers, such as Safari, don't downcase hostname and href
					var originalSourceHostName = sourceElement.hostname || getHostName(sourceElement.href),
						sourceHostName = originalSourceHostName.toLowerCase(),
						sourceHref = sourceElement.href.replace(originalSourceHostName, sourceHostName),
						scriptProtocol = new RegExp('^(javascript|vbscript|jscript|mocha|livescript|ecmascript|mailto):', 'i');

					// ignore script pseudo-protocol links
					if (!scriptProtocol.test(sourceHref)) {
						// track outlinks and all downloads
						linkType = getLinkType(sourceElement.className, sourceHref, isSiteHostName(sourceHostName));
						if (linkType) {
							// urldecode %xx
							sourceHref = urldecode(sourceHref);
							logLink(sourceHref, linkType);
						}
					}
				}
			}

			/*
			 * Handle click event
			 */
			function clickHandler(evt) {
				var button,
					target;

				evt = evt || windowAlias.event;
				button = evt.which || evt.button;
				target = evt.target || evt.srcElement;

				// Using evt.type (added in IE4), we avoid defining separate handlers for mouseup and mousedown.
				if (evt.type === 'click') {
					if (target) {
						processClick(target);
					}
				} else if (evt.type === 'mousedown') {
					if ((button === 1 || button === 2) && target) {
						lastButton = button;
						lastTarget = target;
					} else {
						lastButton = lastTarget = null;
					}
				} else if (evt.type === 'mouseup') {
					if (button === lastButton && target === lastTarget) {
						processClick(target);
					}
					lastButton = lastTarget = null;
				}
			}

			/*
			 * Add click listener to a DOM element
			 */
			function addClickListener(element, enable) {
				if (enable) {
					// for simplicity and performance, we ignore drag events
					addEventListener(element, 'mouseup', clickHandler, false);
					addEventListener(element, 'mousedown', clickHandler, false);
				} else {
					addEventListener(element, 'click', clickHandler, false);
				}
			}

			/*
			 * Add click handlers to anchor and AREA elements, except those to be ignored
			 */
			function addClickListeners(enable) {
				if (!linkTrackingInstalled) {
					linkTrackingInstalled = true;

					// iterate through anchor elements with href and AREA elements

					var i,
						ignorePattern = getClassesRegExp(configIgnoreClasses, 'ignore'),
						linkElements = documentAlias.links;

					if (linkElements) {
						for (i = 0; i < linkElements.length; i++) {
							if (!ignorePattern.test(linkElements[i].className)) {
								addClickListener(linkElements[i], enable);
							}
						}
					}
				}
			}

			/*
			 * Browser features (plugins, resolution, cookies)
			 */
			function detectBrowserFeatures() {
				var i,
					mimeType,
					pluginMap = {
						// document types
						pdf: 'application/pdf',

						// media players
						qt: 'video/quicktime',
						realp: 'audio/x-pn-realaudio-plugin',
						wma: 'application/x-mplayer2',

						// interactive multimedia
						dir: 'application/x-director',
						fla: 'application/x-shockwave-flash',

						// RIA
						java: 'application/x-java-vm',
						gears: 'application/x-googlegears',
						ag: 'application/x-silverlight'
					};

				// general plugin detection
				if (navigatorAlias.mimeTypes && navigatorAlias.mimeTypes.length) {
					for (i in pluginMap) {
						if (Object.prototype.hasOwnProperty.call(pluginMap, i)) {
							mimeType = navigatorAlias.mimeTypes[pluginMap[i]];
							browserFeatures[i] = (mimeType && mimeType.enabledPlugin) ? '1' : '0';
						}
					}
				}

				// Safari and Opera
				// IE6/IE7 navigator.javaEnabled can't be aliased, so test directly
				if (typeof navigator.javaEnabled !== 'unknown' &&
						isDefined(navigatorAlias.javaEnabled) &&
						navigatorAlias.javaEnabled()) {
					browserFeatures.java = '1';
				}

				// Firefox
				if (isFunction(windowAlias.GearsFactory)) {
					browserFeatures.gears = '1';
				}

				// other browser features
				browserFeatures.res = screenAlias.width + 'x' + screenAlias.height;
				browserFeatures.cookie = hasCookies();
			}

/*<DEBUG>*/
			/*
			 * Register a test hook. Using eval() permits access to otherwise
			 * privileged members.
			 */
			function registerHook(hookName, userHook) {
				var hookObj = null;

				if (isString(hookName) && !isDefined(registeredHooks[hookName]) && userHook) {
					if (isObject(userHook)) {
						hookObj = userHook;
					} else if (isString(userHook)) {
						try {
							eval('hookObj =' + userHook);
						} catch (e) { }
					}

					registeredHooks[hookName] = hookObj;
				}
				return hookObj;
			}
/*</DEBUG>*/

			/************************************************************
			 * Constructor
			 ************************************************************/

			/*
			 * initialize tracker
			 */
			detectBrowserFeatures();
			updateDomainHash();

/*<DEBUG>*/
			/*
			 * initialize test plugin
			 */
			executePluginMethod('run', registerHook);
/*</DEBUG>*/

			/************************************************************
			 * Public data and methods
			 ************************************************************/

			return {
/*<DEBUG>*/
				/*
				 * Test hook accessors
				 */
				hook: registeredHooks,
				getHook: function (hookName) {
					return registeredHooks[hookName];
				},
/*</DEBUG>*/

				/**
				 * Get visitor ID (from first party cookie)
				 *
				 * @return string Visitor ID in hexits (or null, if not yet known)
				 */
				getVisitorId: function () {
					return (loadVisitorIdCookie())[1];
				},

				/**
				 * Get the visitor information (from first party cookie)
				 *
				 * @return array
				 */
				getVisitorInfo: function () {
					return loadVisitorIdCookie();
				},

				/**
				 * Specify the Piwik server URL
				 *
				 * @param string trackerUrl
				 */
				setTrackerUrl: function (trackerUrl) {
					configTrackerUrl = trackerUrl;
				},

				/**
				 * Specify the site ID
				 *
				 * @param int|string siteId
				 */
				setSiteId: function (siteId) {
					configTrackerSiteId = siteId;
				},

				/**
				 * Set delay for link tracking (in milliseconds)
				 *
				 * @param int delay
				 */
				setLinkTrackingTimer: function (delay) {
					configTrackerPause = delay;
				},

				/**
				 * Set list of file extensions to be recognized as downloads
				 *
				 * @param string extensions
				 */
				setDownloadExtensions: function (extensions) {
					configDownloadExtensions = extensions;
				},

				/**
				 * Specify additional file extensions to be recognized as downloads
				 *
				 * @param string extensions
				 */
				addDownloadExtensions: function (extensions) {
					configDownloadExtensions += '|' + extensions;
				},

				/**
				 * Set array of domains to be treated as local
				 *
				 * @param string|array hostsAlias
				 */
				setDomains: function (hostsAlias) {
					configHostsAlias = isString(hostsAlias) ? [hostsAlias] : hostsAlias;
					configHostsAlias.push(domainAlias);
				},

				/**
				 * Set array of classes to be ignored if present in link
				 *
				 * @param string|array ignoreClasses
				 */
				setIgnoreClasses: function (ignoreClasses) {
					configIgnoreClasses = isString(ignoreClasses) ? [ignoreClasses] : ignoreClasses;
				},

				/**
				 * Override referrer
				 *
				 * @param string url
				 */
				setReferrerUrl: function (url) {
					configReferrerUrl = url;
				},

				/**
				 * Override url
				 *
				 * @param string url
				 */
				setCustomUrl: function (url) {
					configCustomUrl = resolveRelativeReference(locationHrefAlias, url);
				},

				/**
				 * Override document.title
				 *
				 * @param string title
				 */
				setDocumentTitle: function (title) {
					configTitle = title;
				},

				/**
				 * Set array of classes to be treated as downloads
				 *
				 * @param string|array downloadClasses
				 */
				setDownloadClasses: function (downloadClasses) {
					configDownloadClasses = isString(downloadClasses) ? [downloadClasses] : downloadClasses;
				},

				/**
				 * Set array of classes to be treated as outlinks
				 *
				 * @param string|array linkClasses
				 */
				setLinkClasses: function (linkClasses) {
					configLinkClasses = isString(linkClasses) ? [linkClasses] : linkClasses;
				},

				/**
				 * Strip hash tag (or anchor) from URL
				 *
				 * @param bool enableFilter
				 */
				discardHashTag: function (enableFilter) {
					configDiscardHashTag = enableFilter;
				},

				/**
				 * Set first-party cookie name prefix
				 *
				 * @param string cookieNamePrefix
				 */
				setCookieNamePrefix: function (cookieNamePrefix) {
					configCookieNamePrefix = cookieNamePrefix;
				},

				/**
				 * Set first-party cookie domain
				 *
				 * @param string domain
				 */
				setCookieDomain: function (domain) {
					configCookieDomain = domainFixup(domain);
					updateDomainHash();
				},

				/**
				 * Set first-party cookie path
				 *
				 * @param string domain
				 */
				setCookiePath: function (path) {
					configCookiePath = path;
					updateDomainHash();
				},

				/**
				 * Set visitor cookie timeout (in seconds)
				 *
				 * @param int timeout
				 */
				setVisitorCookieTimeout: function (timeout) {
					configVisitorCookieTimeout = timeout * 1000;
				},

				/**
				 * Set session cookie timeout (in seconds)
				 *
				 * @param int timeout
				 */
				setSessionCookieTimeout: function (timeout) {
					configSessionCookieTimeout = timeout * 1000;
				},

				/**
				 * Set referral cookie timeout (in seconds)
				 *
				 * @param int timeout
				 */
				setReferralCookieTimeout: function (timeout) {
					configReferralCookieTimeout = timeout * 1000;
				},

				/**
				 * Handle do-not-track requests
				 *
				 * @param bool enable If true, don't track if user agent sends 'do-not-track' header
				 */
				setDoNotTrack: function (enable) {
					var dnt = navigatorAlias.doNotTrack || navigatorAlias.msDoNotTrack;

					configDoNotTrack = enable && (dnt === 'yes' || dnt === '1');
				},

				/**
				 * Add click listener to a specific link element.
				 * When clicked, Piwik will log the click automatically.
				 *
				 * @param DOMElement element
				 * @param bool enable If true, use pseudo click-handler (mousedown+mouseup)
				 */
				addListener: function (element, enable) {
					addClickListener(element, enable);
				},

				/**
				 * Install link tracker
				 *
				 * The default behaviour is to use actual click events. However, some browsers
				 * (e.g., Firefox, Opera, and Konqueror) don't generate click events for the middle mouse button.
				 *
				 * To capture more "clicks", the pseudo click-handler uses mousedown + mouseup events.
				 * This is not industry standard and is vulnerable to false positives (e.g., drag events).
				 *
				 * There is a Safari/Chrome/Webkit bug that prevents tracking requests from being sent
				 * by either click handler.  The workaround is to set a target attribute (which can't
				 * be "_self", "_top", or "_parent").
				 *
				 * @see https://bugs.webkit.org/show_bug.cgi?id=54783
				 *
				 * @param bool enable If true, use pseudo click-handler (mousedown+mouseup)
				 */
				enableLinkTracking: function (enable) {
					if (hasLoaded) {
						// the load event has already fired, add the click listeners now
						addClickListeners(enable);
					} else {
						// defer until page has loaded
						registeredOnLoadHandlers.push(function () {
							addClickListeners(enable);
						});
					}
				},

				/**
				 * Set heartbeat (in seconds)
				 *
				 * @param int minimumVisitLength
				 * @param int heartBeatDelay
				 */
				setHeartBeatTimer: function (minimumVisitLength, heartBeatDelay) {
					var now = new Date();

					configMinimumVisitTime = now.getTime() + minimumVisitLength * 1000;
					configHeartBeatTimer = heartBeatDelay * 1000;
				},

				/**
				 * Frame buster
				 */
				killFrame: function () {
					if (windowAlias.location !== windowAlias.top.location) {
						windowAlias.top.location = windowAlias.location;
					}
				},

				/**
				 * Redirect if browsing offline (aka file: buster)
				 *
				 * @param string url Redirect to this URL
				 */
				redirectFile: function (url) {
					if (windowAlias.location.protocol === 'file:') {
						windowAlias.location = url;
					}
				},

				/**
				 * Count sites in pre-rendered state
				 *
				 * @param bool enable If true, track when in pre-rendered state
				 */
				setCountPreRendered: function (enable) {
					configCountPreRendered = enable;
				},

				/**
				 * Manually log a click from your own code
				 *
				 * @param string sourceUrl
				 * @param string linkType
				 */
				trackLink: function (sourceUrl, linkType) {
					trackCallback(function () {
						logLink(sourceUrl, linkType);
					});
				},

				/**
				 * Log visit to this page
				 *
				 * @param string customTitle
				 */
				trackPageView: function (customTitle) {
					trackCallback(function () {
						logPageView(customTitle);
					});
				},

/*<SNOWPLOW> New SnowPlow functionality */

                /**
                 * Specify the SnowPlow tracking account. We use the account ID
                 * to define the tracker URL for SnowPlow. 
                 *
                 * @param string accountId
                 */
                setAccount: function (accountId) {
                    configTrackerUrl = trackerUrlFromAccountId(accountId);
                },

                /**
                 * Track an event happening on this page
                 *
                 * @param string category The name you supply for the group of objects you want to track
                 * @param string action A string that is uniquely paired with each category, and commonly used to define the type of user interaction for the web object
                 * @param string label (optional) An optional string to provide additional dimensions to the event data
                 * @param int|float|string value (optional) An integer that you can use to provide numerical data about the user event
                 */
                trackEvent: function (category, action, label, property, value) {
                    logEvent(category, action, label, property, value);                   
                },

                /**
                 * Track an ad being served
                 *
                 * @param string bannerId Identifier for the ad banner displayed
                 * @param string campaignId (optional) Identifier for the campaign which the banner belongs to
                 * @param string advertiserId (optional) Identifier for the advertiser which the campaign belongs to
                 * @param string userId (optional) Ad server identifier for the viewer of the banner
                 */
                 trackImpression: function (bannerId, campaignId, advertiserId, userId) {
                     logImpression(bannerId, campaignId, advertiserId, userId);
                 }
/*</SNOWPLOW>*/

			};
		}

		/************************************************************
		 * Proxy object
		 * - this allows the caller to continue push()'ing to _snaq
		 *   after the Tracker has been initialized and loaded
		 ************************************************************/

		function TrackerProxy() {
			return {
				push: apply
			};
		}

		/************************************************************
		 * Constructor
		 ************************************************************/

		// initialize the SnowPlow singleton
		addEventListener(windowAlias, 'beforeunload', beforeUnloadHandler, false);
		addReadyListener();

		Date.prototype.getTimeAlias = Date.prototype.getTime;

		asyncTracker = new Tracker();

		for (i = 0; i < _snaq.length; i++) {
			apply(_snaq[i]);
		}

		// replace initialization array with proxy object
		_snaq = new TrackerProxy();

		/************************************************************
		 * Public data and methods
		 ************************************************************/

		return {
			/**
			 * Add plugin
			 *
			 * @param string pluginName
			 * @param Object pluginObj
			 */
			addPlugin: function (pluginName, pluginObj) {
				plugins[pluginName] = pluginObj;
			},

/*<SNOWPLOW> Updated SnowPlow functionality */
            /**
             * SnowPlow replacement for Piwik getTracker function
             * The function returns a Tracker object
             * However, rather than passing in a piwikUrl and siteID,
             * it takes a SnowPlow account ID, and constructs the  
             * Url from it. (We do not use siteIds as part of SnowPlow)
             * 
             * @param string accountId
             */
            getTracker: function (accountId) {
                return new Tracker(accountId);
            }, 
/*<SNOWPLOW>*/

			/**
			 * Get internal asynchronous tracker object
			 *
			 * @return Tracker
			 */
			getAsyncTracker: function () {
				return asyncTracker;
			}
		};
	}());