Not clear expired content on CacheManager init

[jlsandrin]

I'm using Cache to store JSON coming from the server. This content is updated everyday, so I'm setting it's expiration date to be the day it was downloaded at 11:59 PM. this works just fine and the content is expired and re downloaded the next day.

The problem I'm facing is that, due to business rules, I need to return expired content (so I can have something to show user), identify that this content has expired and download the new version. And then update view with this new content and cache it.

Is there any way to flag Cache to not clear expired data on initialization, and when receiving some notifications?

[zenangst]

@jlsandrin hey man, right now we don't have a way of opting out from clearing the expired objects when CacheManager gets initialized. This is by design so that we don't keep outdated content around. With that said, couldn't you just set the expiration date to be nil when storing the objects? That way they won't be cleared when CacheManager initializes?

[zenangst]

This feels pseudo related to #117.

[zenangst]

@vadymmarkov could this be solved by adding a small configuration enum.

enum CacheExpirationMode {
  case auto, manual
}

.auto would be the default to not break the current implementation. And when you set it to .manual, it would simply opt out from doing any for of cleanup during application launch. This would mean that the developer would have to handle that manually (which I think is okay).

[vadymmarkov]

@zenangst Yes, that should work I think.

[jlsandrin]

I agree with clearing objects on init. I personally prefer an option like that, but unfortunately this app can't work this way.

The problem with setting the expiration to nil is that I can't handle if content is "old" or not (or at least I couldn't find a way). I download something new whenever expiration date is older than current date, while not deleting what is in store.

.manual option would be perfect for what I need.

[zenangst]

@jlsandrin ohai, I whipped up a small PR to implement this feature, you can find it here #118

[jlsandrin]

Awesome, you guys rock!

[zenangst]

@jlsandrin let us know how it works out! It should be on master now. Closing the issue.