Hi we have a mobile app (iOS and Android) that needs to display a few web pages using embedded UIWebView or WebView. These pages need to support offline browsing for 7-10 days. We are considering two alternatives - AppCache and cache-control header:
cache-control: max-age=604800
We ran many proof of concepts using both approaches. Both approaches seem to give us what we need. Cache-control seems to have the slight advantage that we can set its value in web server configuration using wildcard for all JS, CSS and image files. Where as for cache manifest we need to list each file individually.
Having said all that, I do not find anyone attempting to build an offline app using cache-control. Nearly all article and blog post uses AppCache. Is there something I am missing here?
One problem with using cache-control for offline is that the user would need to visit all the pages in the app before leaving, otherwise they would not get cached for use next time they visit. The App Cache lists all the required pages and caches them all straight away.
cache-control is also not designed to support offline apps (it would seem), and there are catches, such as browsers not loading from the cache in some circumstances. So you cannot guarantee that the browser will not try to send a request for the resource while offline (resulting in the page showing network failure).
Basically, if you want it to work reliably, you should use App Cache or Service Workers.