AppCache for 24 hours?

Recently I started using the

<html manifest="cache.appcache">

method for storing assets in my PhoneGap application.

Is it possible to use appcache but have it check every 24 hours for an updated version of the cached items?

Solution

To do so you have to generate the cache.appcache dynamically and add a comment line which changes in the desired interval:

    CACHE MANIFEST
    # 2012-07-31 14:30

    css/default.css
    ...

and after 24 hours:

    CACHE MANIFEST
    # 2012-08-01 14:30

    css/default.css
    ...

If changes in the content of that file happens a browser loads all cached data again.

NOTE: just a touch in file system does not bring the expected result. The content itself has to change.