eTag support

[danielebogo]

Hi there 👋
I know from some old closed issue there was a wiki page 👉 here to help implementing NSCache.
I need to replicate the SDWebImageOptions.refreshCached behaviour in some way.

Any help/idea?

[onevcat]

Hi,

I have to say the ETag support was never an "official" part of Kingfisher. It is using a URL-based way to cache the result.

I am not sure what SDWebImageOptions.refreshCached is doing. But it sounds like you need to force a refresh when loading the image. If that is true, .forcerefresh might be identical, which will always load the image from the URL instead of using a cached one.

imageView.kf.setImage(with: url, options: [.forcerefresh])

[danielebogo]

Thanks @onevcat !
If I'm not wrong with that flag it uses NSCache instead of SDWebImage cache and deals with images changing behind the same request URL. But I have no idea if it displays the in memory image first while is fetching the HTTP response.

[danielebogo]

Btw I think I find a solution to what I'm trying to achieve. I always want the ImageFormat stored as image property and I think I can achieve that with a custom Processor.

[choli]

What I ended up, and seems to be a way to go, is to set two options:
.forceRefresh, // make sure to skip the Kingfisher cache
.requestModifier(MyRequestModifier()), // where we reset the cachePolicy on the URLRequest to the default -useProtocolCachePolicy.

Does that seem about right?