Fingerprinting to dynamically enable caching/ Caching dynamic content

While reading the caching tutorial from google came across with the section about using fingerprinting concept for caching content which changes regularly. Below is the explanation from google team.

"For resources that change occasionally, you can have the browser cache the resource until it changes on the server, at which point the server tells the browser that a new version is available. You accomplish this by embedding a fingerprint of the resource in its URL (i.e. the file path). When the resource changes, so does its fingerprint, and in turn, so does its URL. As soon as the URL changes, the browser is forced to re-fetch the resource. Fingerprinting allows you to set expiry dates long into the future even for resources that change more frequently than that. Of course, this technique requires that all of the pages that reference the resource know about the fingerprinted URL, which may or may not be feasible, depending on how your pages are coded."

I am writing the code in php to implement this concept and will share with you all soon.