Aggressive JavaScript caching

Question

I\'ve run into a problem where I make changes to a few JavaScript files that are referenced in an HTML file, but the browser doesn\'t see the changes. It holds onto the copy

Answer 1

I am also of the method of just renaming things. It never fails, and is fairly easy to do.

Answer 2

For what it is worth, I saw deviantART site, quite a big one, serving their JS files as 54504.js. I just checked and see they now serve them as v6core.css?-5855446573 v6core_jc.js?4150339741 etc.

If the problem of query string comes from the server, I suppose you can control that more or less.

Answer 3

With every release, we simply prepend a monotonically increasing integer to the root path of all our static assets, which forces the client to reload (we've seen the query string method break in IE6 before). For example:

• Release 1: http://www.foo.com/1/js/foo.js
• Release 2: http://www.foo.com/2/js/foo.js

It requires rejiggering links with each release, but we've built functionality to automatically change the links into our deployment tools.

Once you do this, you can use Expires/Cache-Control headers that let the client cache JS resources "forever", since the path changes with each release, which i think is what @JasonCohen was getting at.