Client-side caching

[julianrubisch]

There are two ways in which this could be tackled:

1. the „canonical“ way would be via PWA/Service worker. The problem is that only one SW per domain can exist, so people would have to integrate this with their own implementations. This would boil down to a (hard and ungrateful) documentation task.

2. We could also go and roll our own implementation, as for example with the Turbolinks cache store and sessionStorage. The problem is that it only holds a few MB and isn’t expireable: https://stackoverflow.com/questions/15171711/expiry-of-sessionstorage

this could also be a case for IndexedDB/localForage, but still we would have to code the expiration logic ourselves: https://stackoverflow.com/questions/35511033/how-to-apply-expiry-times-to-keys-in-html5-indexeddb/35518068

That said, we could provide a unified interface for both Turbolinks cache storage and fragment caching via localForage