[Javascript] 1 MORE Question: Navigation Control - No back button?

[Josiah Gordon]

Rodney,

> I would like to know if this server side
> application to the header has a better
> performance than adding
> <meta http-equiv="Pragma" content="no-cache">
> <meta http-equiv="Cache-Control" content="no-cache">
> to the HEAD ?

Absolutely. The meta tags are not supported by many devices and for good
reason. Netscape 4.5 has a bug with the no-cache meta tag and all versions
of IE are finicky (at best) with the cache-control meta tags.

The reason MS has never cared is because only HTTP headers should *really*
have the right to control cache. This is because of proxy servers: Imagine
AOL - they cache every web page requested through their software to save
bandwidth. Now imagine, that instead of reading the >1K headers of the
HTTP/1.1 responses, they had to open and parse every HTML page that passed
through their proxies. That's a lot of extra (and unneeded) overhead when
headers are efficient, standardized, and well documented.

If you want to disable caching, headers are the only single reliable way to
do it.

> I have been thinking of a script that
> might compare system date to document.lastModfied for example.

May I ask what your goal is? Are you dealing with dynamic code from a
database? If so, you should use headers. If not, then leave caching to the
browser since most browsers handle static pages well.



--Josiah Gordon


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