UIKit and AppKit

Load images into UIImageView, NSImageView, and UIButton using the NukeExtensions module.

Overview

NukeExtensions is a companion module that provides free functions for loading images into UIImageView, NSImageView, and UIButton. Add it to your project via Swift Package Manager alongside Nuke.

Loading Images into UIImageView

The most common use case is loading an image into a UIImageView.

swift

import NukeExtensions

NukeExtensions.loadImage(with: url, into: imageView)

This uses ImagePipeline/shared and handles caching automatically. The previous request for that image view is cancelled when a new one starts — so it's safe to call from cellForItemAt without extra bookkeeping.

Cell Reuse

In collection and table views, cells are reused. Nuke handles cancellation automatically: starting a new loadImage call on a view cancels its previous request.

swift

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as! ImageCell
    // Any previous request on this cell's imageView is cancelled automatically.
    NukeExtensions.loadImage(with: items[indexPath.item].imageURL, into: cell.imageView)
    return cell
}

Placeholder and Failure Images

Use ImageLoadingOptions to specify a placeholder shown while the image loads and a failure image shown on error.

swift

var options = ImageLoadingOptions()
options.placeholder = UIImage(named: "placeholder")
options.failureImage = UIImage(named: "error")

NukeExtensions.loadImage(with: url, options: options, into: imageView)

Transitions

Apply a cross-fade or a custom transition when the image loads.

swift

var options = ImageLoadingOptions()
options.transition = .fadeIn(duration: 0.3)

NukeExtensions.loadImage(with: url, options: options, into: imageView)

To set a global default for all image views, configure ImageLoadingOptions.shared.

swift

ImageLoadingOptions.shared.transition = .fadeIn(duration: 0.25)

Processors and Request Options

Pass an ImageRequest to apply processors or change request priority.

swift

let request = ImageRequest(
    url: url,
    processors: [.resize(width: 320)]
)
NukeExtensions.loadImage(with: request, into: imageView)

Tracking Progress and Completion

Use the completion closure to respond to success or failure.

swift

NukeExtensions.loadImage(with: url, into: imageView) { result in
    switch result {
    case .success(let response):
        print("Loaded image from: \(response.urlResponse?.url?.absoluteString ?? "cache")")
    case .failure(let error):
        print("Failed to load image: \(error)")
    }
}

Loading into UIButton

NukeExtensions also supports loading images into UIButton.

swift

NukeExtensions.loadImage(with: url, into: button, for: .normal)

For full NukeExtensions documentation, see the NukeExtensions repository and its documentation site.