MartinPeck

Hello - sincerely hoping someone out there will be able to help with this, or at least have a good idea on what's going on. I have created a 'Single Page Application' (SPA) type website, and have used PHP on the server-side. At present, nearly all my content files (XML, JPEGs, XSLT, CSS) are generated from PHP scripts. My design uses many source files, and some pages have many small images, so file caching by the client browser is very important. I have set HTTP Cache-Control response headers on everything, to inform the browser that it can and should cache everything. (Content changes get picked up when a version number changes in the URL.) So far, so good - or so I thought. My problem is that both Safari and Chrome on iOS do fresh requests of EVERYTHING that's come from PHP, every time the user opens the phone from screen-lock. So the site is fast and slick with everything loaded into cache, until a 20 second pause with the phone locked, and then everything is dog slow again the first time content is viewed. For my use-case, this is a huge usability (and server load) problem. I've noticed that this refreshing of content DOESN'T happen for regular static files. (I have a folder of static file PNG images, and these never get re-requested.) How can I make all the PHP-generated content appear to the browser to be static files, so that the browser's heuristics don't mistrust them and assume they will be changing despite the HTTP headers?????! I can't believe I'm having this problem, honestly. Never seen anything like it before, with browsers ignoring these Cache-Control directives. There's something really messed up with the logic on mobile devices....