forcing updates to cached image / PDF files

[Dubb]

My experience modern html/javascript/etc is pretty limited. I produce alot of graphic content for various websites, and am quite good at it, and because of that my firm has put me in charge of managing one of our sites that was produced by someone else.

It has a number of images and downloadable PDFs that are updated on occasion. Recently we discovered that if a visitor has an image or pdf in their cache, they won't download the new version unless they clear their cache first (filenames are the same)

Is there a quick/easy way to fix this? preferably we would like to prevent caching of new files but also force an update of any that may have been downloaded in the past, without having to make different files for each update

T.I.A.

 

[gsaldivar]

Off the top of my head: you can set certain tags to prevent caching, but its ultimately up to your visitors' web browser to decide whether or not to honor the tag and cache/not cache as you are requesting. Why not just increment the filename as the content changes? This way, even visitors with an older cached version will see the updated filename and always treat the content as "new". Other than tags, I don't think you have much control over whether or not a visitors' web browser retains a copy of what has been downloaded.

 

[lxskllr]

Originally posted by: gsaldivar
Why not just increment the filename as the content changes? This way, even visitors with an older cached version will see the updated filename and always treat the content as "new".

I think this is the best way to go. I'd use the file name with the date appended. That'll also make it easier for you to keep track of changes... MyPDF100909.pdf