javascript

Chapter 8: The Browser Object Model
If this page is loaded into a web browser, it will redirect to www.wrox.com after a second. At that point,
the Back button will be disabled and you won ’ t be able to navigate back to this example page without
typing in the complete URL again.
The last method of location is reload() , which reloads the currently displayed page. When reload() is
called with no argument, the page is reloaded in the most efficient way possible, which is to say that the
page may be reloaded from the browser cache if it hasn ’ t changed since the last request. To force a reload
from the server, pass in true as an argument like this:
location.reload();
location.reload(true);
//reload - possibly from cache
//reload - go back to the server
Any code located after a reload() call may or may not be executed, depending on factors such as
network latency and system resources. For this reason, it is best to have reload() as the last line of code.
The navigator Object
Originally introduced in Netscape Navigator 2.0, the navigator object has become a de facto standard
for browser identification on the client. Though some browsers offer alternate ways to provide the same
or similar information (for example, window.clientInformation in IE and window.opera in Opera),
the navigator object is common among all JavaScript - enabled web browsers. As with other BOM
objects, each browser supports its own set of properties. The following table lists each available property
and method, along with which browser versions support it.
Property/Method Description IE Firefox
Safari/
Chrome
Opera
appCodeName
The name of the browser.
Typically ” Mozilla ” even in
non - Mozilla browsers.
3.0+ 1.0+ 1.0+ 7.0+
appName Full browser name. 3.0+ 1.0+ 1.0+ 7.0+
appMinorVersion Extra version information. 4.0+ — — 9.5+
appVersion
Browser version. Typically
does not correspond to the
actual browser version.
3.0+ 1.0+ 1.0+ 7.0+
buildID Build number for the browser. — 2.0+ — —
cookieEnabled
cpuClass
Indicates if cookies are
enabled.
The type of processor used on
the client computer ( “ x86 ” ,
” 68K ” , ” Alpha ” , ” PPC ” , or
” Other “ ).
4.0+ 1.0+ 1.0+ 7.0+
4.0+ — — —
(continued)
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