Hmmm, I'm staring at web sites that -do- update their graphic content, such as weather display sites and the MRTG (network graph stats) program, and I don't see anything like a variable URL. How do they manage it? The only new item I see is the use of: <META HTTP-EQUIV="Refresh" CONTENT=300> <META HTTP-EQUIV="Expires" CONTENT="...a date"> While this would cause the HTML to refreshed periodically, how are they getting the browser to re-fetch the *images*? I've captured the HTML source for several iterations and the <IMG SRC="blah"...> part never changes, so I would expect the same graphic would keep appearing on each cycle. -Jeff Rush On Tue, 19 Oct 1999 09:16:24 +1000, Anthony Baxter wrote:
Yep. Browsers suck. They cache images regardless. The disgusting hack is to always call your image with the current time in the URL - eg. <img src="/your/image/method?dummy_ts=<dtml-var "ZopeTime().timeTime()">"> /your/image/method should feel entirely free to ignore dummy_ts.
This way the image has a different URL, and so the browser doesn't use a cached one.
When you're producing on-the-fly live statistics as a graph, this hideous misfeature is a complete pain in the clacker.