I'm caching partials with the intention that Ajax requests can receive them directly from Nginx without hitting my Rails server.

I've tried :

if ($x_requested_with = XMLHttpRequest) {
rewrite ^(.*)$ /ajax/$1 break;
}

which gives me : unknown "x_requested_with" variable.

What should be the approach here?

Thanks.

Ok, it would help if I wasn't an idiot :-)

if ($http_x_requested_with = XMLHttpRequest) {
rewrite ^(.*)$ /ajax/$1 break;
}

I found the http_ tip after more digging around.