Brf wrote:Webbrowsers typically cache stylesheets if they can. This is especially true with the Prosilver stylesheet, which is created by style.php. Since style.php's timestamp has not changed, your webbrowser does not know there has been a change,
That is not entirely correct. style.php is an executable file, its time stamp is irrelevant. When browser sends IF_MODIFIED_SINCE header to check if file has been modified, PHP still executes script. Its up to script to check for that HTTP header.
However, style.php sends expiration date http header that causes problem. It tells browser to cache stylesheet for 7 days, so browser doesn't even bother checking if stylesheet has been updated because forum told it to keep cache for 7 days. style.php sends that header only if theme hasn't been changed in last 30 minutes.
Its weird behavior and something that is gone from phpBB 3.1
Best way to deal with that is to enable option "recompile stale style components". You can find it in admin control panel -> load settings. Enable it before performing any edits to any style components, disable it after you've done editing and made sure all changes work. It will remove need to purge phpBB cache after each template or theme edit.