javascript

Chapter 9: Client Detection
(continued)
var browser = {
//browsers
ie: 0,
firefox: 0,
safari: 0,
konq: 0,
opera: 0,
chrome: 0,
safari: 0,
};
//specific version
ver: null
}();
var system = {
win: false,
mac: false,
x11: false
};
//detection of rendering engines/platforms/devices here
return {
engine: engine,
browser: browser,
system: system
};
This code introduces a new system variable that has three properties. The win property indicates if the
platform is Windows, mac indicates Mac, and x11 indicates Unix. Unlike rendering engines, platform
information is typically very limited, without access to operating systems or versions. Of these three
platforms, browsers regularly report only Windows versions. For this reason, each of these properties is
represented initially by a Boolean false instead of a number (as with the rendering - engine properties).
To determine the platform, it ’ s much easier to look at navigator.platform than to look at the user -
agent string, which may represent platform information differently across browsers. The possible values
for navigator.platform are ” Win32 ” , ” Win64 ” , ” MacPPC ” , ” MacIntel ” , ” X11 ” , and ” Linux i686 ” ,
which are consistent across browsers. The platform - detection code is very straightforward, as you can
see in the following example:
var p = navigator.platform;
system.win = p.indexOf(“Win”) == 0;
system.mac = p.indexOf(“Mac”) == 0;
system.x11 = (p.indexOf(“X11”) == 0) || (p.indexOf(“Linux”) == 0);
This code uses the indexOf() method to look at the beginning of the platform string. Even though
” Win32 ” is currently the only Windows string supported, Windows is moving toward a 64 - bit
architecture that may mean the introduction of a ” Win64 ” platform. To prepare for this, the platform -
detection code simply looks for the string ” Win ” at the beginning of the platform string. Testing for a
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