[wp-hackers] Javascript

[Andy Skelton]

On 9/25/06, Andy Staines <andy at yellowswordfish.com> wrote:
> > What do you mean by "on startup"?
>
> bad phrase choice. Initialisation perhaps? I realise this is with
> every page load but I still don't know everything that's going on in
> there!

This is still pretty vague. This is a WordPress list so I'll assume
you mean that you want this information available at the "init"
action.

There is no such information available in core. As I said before,
browsers never expose this info in the request headers. You have to
either make the browser do this, or just send both versions of the
page and write it so that the js code upgrades the non-js HTML.

If you insist on "knowing" whether the browser can do js, possibly the
leanest way to accomplish it would be with a plugin that did the
following:

1. Check for a cookie named "my_plugin_js_test" or similar.
2. If the cookie is set to 'on', the browser probably has js on.
3. Else If the cookie is set to 'off', add some js to the page that will:
 a. Set the cookie to 'on' and
 b. Reload the page, returning you to step 1.
4. Else the cookie is missing, invalid or expired, so do the following:
 a. Set the cookie to 'off' and
 b. Add the js from step 3 (set 'on', reload)

If JS is enabled and the cookie is not set to 'on', this program will
set the cookie 'on' and reload. Otherwise it'll set the cookie to
'off' and continue loading.

See how convoluted that is? I advise against it. :-)

Andy