Use for local loading of embedded JPEG thumbnails

[minorbug]

I have a use case for using Nuke's LazyImage to show hundreds, or even thousands, of local images. I have this working locally but it has to read the whole image before displaying. These local images are 20-80mp in size, and most have embedded thumbnails.

Is there a way to modify the loading process to quickly load thumbnails first, then return the image when its fully loaded?

[kean]

Hey, I was just looking into these APIs yesterday. Yes, there is a way to fetch the original thumbnails using ImageRequest.ThumbnailOptions. It would look something like this:

// Code wasn't tested
func test() async throws {
    let url = URL(fileURLWithPath: "...")

    let thumbnail = try await ImagePipeline.shared.image(for: ImageRequest(url: url, userInfo: [
        .thumbnailKey: {
            var options = ImageRequest.ThumbnailOptions(maxPixelSize: 1200)
            options.createThumbnailFromImageAlways = false
            return options
        }()
    ]))

    let image = try await ImagePipeline.shared.image(for: url)
}

I'm not sure why I decided to go with .createThumbnailFromImageAlways set to true when I added this API. I'm going to revisit it in the next major version.

Please, be aware that there is a known issue with combining thumbnail and non-thumbnail requests #705 and it's addressed in the upcoming Nuke 12.6.

As for the local files, yes, the framework fully supports loading images from local files, but the requests will go through URLSession, which is also something to be aware of.