Kiril Mitov blog

How big of a challenge is this?

Technically it is not a great challenge, yet I’ve seen experienced engineers miss this small detail. I’ve missed it a couple of times. Every such case is a load on the support channel of your organisation and on the engineering. So better avoid any caching issues at all.

What’s the solution?

There are many solutions. There is only one that works across all browsers and devices and across all versions of the HTTP protocol that power the internet.The solution is remarkably simple:The browser will look at the URL of the image. If there is a local copy stored for this URL, the browser will use the local copy. If there is no local copy for the URL the browser will request the new image.

Why does the simple solution not work?

I think it does not work because we are humans and we forget. We create a new version of the parent-with-child.png image and we forget to change the name of the image. That’s it. We just forget. Computers on the other hand are good at reminding us of things and of doing dull work that we often forget to do. What we could ask the computer to do is to create a new name for the image everytime we upload a new version.

What’s difficult with fingerprinting?

The difficult part is not the fingerprinting part. What’s difficult is finding every HTML page on your website where the image parent-with-child-a6e0922d83d80151fb73210187a9fb55ee2c5d979177c339f22cb257dead8a56.png is used and replacing this name with parent-with-child-cdc72fa95ca711271e9109b8cab292239afe5d1ba3141ec38b26d9fc8768017b.png.

What needs to be implemented then? What’s the process?

What we need from our process of deploying new versions of images to our website is the following: Ask our illustrator, Antonio in our case, to develop a new version of the parent-and-child.png image.Put this new picture on our website and the computer should magically: – calculate a new checksums of the image and change the name of the parent-and-child.png, eg.