Topic: Cache Busting for static plot images. (Was "old images from data plots")

[miraculon]

Decided that I needed a more descriptive Subject line for this.

I have seen the plots on my site that do not get refreshed by the browser that can be several days old.

I tried a random function for my TOA Systems lightning page a while back and basically forgot about it.

I decided to add this to some of my other "static" (as viewed by browsers) chart images.

It works great and I thought that I would pass it along. I have no idea where I found it from some site.

Here is an example line for my website:

Code: [Select]

<img src="http://www.miraculon.com/weatherdata/barograph.png?rand=<?=rand(1,1000);?>" width=660 height=340>
Note that the ?rand=<?=rand(1,1000);? is the business end of this. It seems to generate a random integer between 1 and 1000. This tricks the browser into seeing it as a new image and loads it.

I don't really understand the nuts and bolts about what is going on and "under the hood" of this obviously server-based function, so don't ask me... 

Greg H.