function detectBrowser()

in tapestry-framework/src/org/apache/tapestry/html/PracticalBrowserSniffer.js [63:162]
87 lines of code
29 McCabe index (conditional complexity)

function detectBrowser()
{
	var oldOnError = window.onerror;
	var element = null;
	
	window.onerror = defaultOnError;

	navigator.OS		= '';
	navigator.version	= 0;
	navigator.org		= '';
	navigator.family	= '';

	var platform;
	if (typeof(window.navigator.platform) != 'undefined')
	{
		platform = window.navigator.platform.toLowerCase();
		if (platform.indexOf('win') != -1)
			navigator.OS = 'win';
		else if (platform.indexOf('mac') != -1)
			navigator.OS = 'mac';
		else if (platform.indexOf('unix') != -1 || platform.indexOf('linux') != -1 || platform.indexOf('sun') != -1)
			navigator.OS = 'nix';
	}

	var i = 0;
	var ua = window.navigator.userAgent.toLowerCase();
	
	if (ua.indexOf('safari') != -1) {
	  navigator.family = 'nn4';
	  navigator.version = 4;
	  navigator.org = 'netscape';
	}
	else if (ua.indexOf('opera') != -1)
	{
		i = ua.indexOf('opera');
		navigator.family	= 'opera';
		navigator.org		= 'opera';
		navigator.version	= parseFloat('0' + ua.substr(i+6), 10);
	}
	else if ((i = ua.indexOf('msie')) != -1)
	{
		navigator.org		= 'microsoft';
		navigator.version	= parseFloat('0' + ua.substr(i+5), 10);
		
		if (navigator.version < 4)
			navigator.family = 'ie3';
		else
			navigator.family = 'ie4'
	}
	else if (typeof(window.controllers) != 'undefined' && typeof(window.locationbar) != 'undefined')
	{
		i = ua.lastIndexOf('/')
		navigator.version = parseFloat('0' + ua.substr(i+1), 10);
		navigator.family = 'gecko';

		if (ua.indexOf('netscape') != -1)
			navigator.org = 'netscape';
		else if (ua.indexOf('compuserve') != -1)
			navigator.org = 'compuserve';
		else
			navigator.org = 'mozilla';
	}
	else if ((ua.indexOf('mozilla') !=-1) && (ua.indexOf('spoofer')==-1) && (ua.indexOf('compatible') == -1) && (ua.indexOf('opera')==-1)&& (ua.indexOf('webtv')==-1) && (ua.indexOf('hotjava')==-1))
	{
	    var is_major = parseFloat(navigator.appVersion);
    
		if (is_major < 4)
			navigator.version = is_major;
		else
		{
			i = ua.lastIndexOf('/')
			navigator.version = parseFloat('0' + ua.substr(i+1), 10);
		}
		navigator.org = 'netscape';
		navigator.family = 'nn' + parseInt(navigator.appVersion);
	}
	else if ((i = ua.indexOf('aol')) != -1 )
	{
		// aol
		navigator.family	= 'aol';
		navigator.org		= 'aol';
		navigator.version	= parseFloat('0' + ua.substr(i+4), 10);
	}

	navigator.DOMCORE1	= (typeof(document.getElementsByTagName) != 'undefined' && typeof(document.createElement) != 'undefined');
	navigator.DOMCORE2	= (navigator.DOMCORE1 && typeof(document.getElementById) != 'undefined' && typeof(document.createElementNS) != 'undefined');
	navigator.DOMHTML	= (navigator.DOMCORE1 && typeof(document.getElementById) != 'undefined');
	navigator.DOMCSS1	= ( (navigator.family == 'gecko') || (navigator.family == 'ie4') );

	navigator.DOMCSS2   = false;
	if (navigator.DOMCORE1)
	{
		element = document.createElement('p');
		navigator.DOMCSS2 = (typeof(element.style) == 'object');
	}

	navigator.DOMEVENTS	= (typeof(document.createEvent) != 'undefined');

	window.onerror = oldOnError;
}