Source: suxess/loggers/userAgentLogger.js

/**
 * JavaScript Client Detection
 * (C) viazenetti GmbH (Christian Ludwig)
 */

'use strict';

/**
 * This class implements logging of user info
 * e.g browser, OS, resolution
 *
 * @constructor
 */
SUXESS.UserAgentLogger = function () {
    this._screenSize = this.getScreenSize();
    this._browser = this.getBrowser();
    this._mobile = this.isMobile();
    this._os = this.getOs();
};

/**
 *
 * @returns {*}
 */
SUXESS.UserAgentLogger.prototype.getScreenSize = function () {

    var width = 0;
    var height = 0;
    if (screen.width) {
        width = (screen.width) ? screen.width : '';
        height = (screen.height) ? screen.height : '';
    }

    return [width, height];

};

/**
 *
 * @returns {string}
 */
SUXESS.UserAgentLogger.prototype.getBrowser = function () {

    // browser
    var nAgt = navigator.userAgent;
    var browser = navigator.appName;
    var nameOffset, verOffset;

    // Opera
    if (nAgt.indexOf('Opera') !== -1) {
        browser = 'Opera';
    }
    // Opera Next
    if (nAgt.indexOf('OPR') !== -1) {
        browser = 'Opera';
    }
    // MSIE
    else if (nAgt.indexOf('MSIE') !== -1) {
        browser = 'Microsoft Internet Explorer';
    }
    // Chrome
    else if (nAgt.indexOf('Chrome') !== -1) {
        browser = 'Chrome';
    }
    // Safari
    else if (nAgt.indexOf('Safari') !== -1) {
        browser = 'Safari';
    }
    // Firefox
    else if (nAgt.indexOf('Firefox') !== -1) {
        browser = 'Firefox';
    }
    // MSIE 11+
    else if (nAgt.indexOf('Trident/') !== -1) {
        browser = 'Microsoft Internet Explorer';
    }
    // Other browsers
    else if ((nameOffset = nAgt.lastIndexOf(' ') + 1) < (verOffset = nAgt.lastIndexOf('/'))) {
        browser = nAgt.substring(nameOffset, verOffset);
        if (browser.toLowerCase() === browser.toUpperCase()) {
            browser = navigator.appName;
        }
    }

    return browser;

};

/**
 *
 * @returns {boolean}
 */
SUXESS.UserAgentLogger.prototype.isMobile = function() {

    var nVer = navigator.appVersion;
    return /Mobile|mini|Fennec|Android|iP(ad|od|hone)/.test(nVer);

};

/**
 *
 * @returns {*}
 */
SUXESS.UserAgentLogger.prototype.getOs = function() {

    var unknown = '-';
    var nAgt = navigator.userAgent;
    var nVer = navigator.appVersion;
    var os = unknown;
    var clientStrings = [
        {s:'Windows 10', r:/(Windows 10.0|Windows NT 10.0)/},
        {s:'Windows 8.1', r:/(Windows 8.1|Windows NT 6.3)/},
        {s:'Windows 8', r:/(Windows 8|Windows NT 6.2)/},
        {s:'Windows 7', r:/(Windows 7|Windows NT 6.1)/},
        {s:'Windows Vista', r:/Windows NT 6.0/},
        {s:'Windows Server 2003', r:/Windows NT 5.2/},
        {s:'Windows XP', r:/(Windows NT 5.1|Windows XP)/},
        {s:'Windows 2000', r:/(Windows NT 5.0|Windows 2000)/},
        {s:'Windows ME', r:/(Win 9x 4.90|Windows ME)/},
        {s:'Windows 98', r:/(Windows 98|Win98)/},
        {s:'Windows 95', r:/(Windows 95|Win95|Windows_95)/},
        {s:'Windows NT 4.0', r:/(Windows NT 4.0|WinNT4.0|WinNT|Windows NT)/},
        {s:'Windows CE', r:/Windows CE/},
        {s:'Windows 3.11', r:/Win16/},
        {s:'Android', r:/Android/},
        {s:'Open BSD', r:/OpenBSD/},
        {s:'Sun OS', r:/SunOS/},
        {s:'Linux', r:/(Linux|X11)/},
        {s:'iOS', r:/(iPhone|iPad|iPod)/},
        {s:'Mac OS X', r:/Mac OS X/},
        {s:'Mac OS', r:/(MacPPC|MacIntel|Mac_PowerPC|Macintosh)/},
        {s:'QNX', r:/QNX/},
        {s:'UNIX', r:/UNIX/},
        {s:'BeOS', r:/BeOS/},
        {s:'OS/2', r:/OS\/2/},
        {s:'Search Bot', r:/(nuhk|Googlebot|Yammybot|Openbot|Slurp|MSNBot|Ask Jeeves\/Teoma|ia_archiver)/} // jshint ignore:line
    ];
    for (var id in clientStrings) {
        var cs = clientStrings[id];
        if (cs.r.test(nAgt)) {
            os = cs.s;
            break;
        }
    }

    var osVersion = unknown;

    if (/Windows/.test(os)) {
        osVersion = /Windows (.*)/.exec(os)[1];
        os = 'Windows';
    }

    switch (os) {
        case 'Mac OS X':
            osVersion = /Mac OS X (10[\.\_\d]+)/.exec(nAgt)[1];
            break;

        case 'Android':
            osVersion = /Android ([\.\_\d]+)/.exec(nAgt)[1];
            break;

        case 'iOS':
            osVersion = /OS (\d+)_(\d+)_?(\d+)?/.exec(nVer);
            osVersion = osVersion[1] + '.' + osVersion[2] + '.' + (osVersion[3] | 0);
            break;
    }

    return [os, osVersion];

};