Feature request: Cache TTL

[devth]

Feature request

This may be counter to the philosophy of this library, but I thought I'd check.

I'd like to cache my data for a specific amount of time in Local Storage, e.g. 24 hours, and only revalidate after that TTL expires.

I found the docs for Local Storage based cache.

I scoured the Options and it looks like I could turn off all the revalidate*** options, but I'm not sure if there's a way to keep track of how old cached items are, and revalidate when expired. It'd be amazing if this was a built in feature.

[piotr-cz]

I think you have to store the timestamp of cache write somehow.

I wrap the data in new object and add a new timestamp property: https://github.com/piotr-cz/swr-idb-cache/blob/v1.0.0-rc.2/src/storage-handler/timestamp.ts
and compare timestamp on Cache#get: https://github.com/piotr-cz/swr-idb-cache/tree/v1.0.0-rc.2#implement-garbage-collector

[devth]

Very cool, thanks for the examples @piotr-cz!

I'd still love it if the API were baked into swr itself.