UIImageView Caching

UIImageView+Additions.swift

import UIKit

/*With GCD*/
extension UIImageView {
    func loadImage(from url: URL?) {
        guard let url = url else { return }
        let cache = URLCache.shared
        let request = URLRequest(url: url)
        
        DispatchQueue.global(qos: .background).async {
            if let data = cache.cachedResponse(for: request)?.data, let image = UIImage(data: data) {
                DispatchQueue.main.async {
                    self.transition(to: image)
                }
            } else {
                URLSession.shared.dataTask(with: request, completionHandler: { data, response, error in
                    if let response = response, let data = data, let image = UIImage(data: data) {
                        let cachedData = CachedURLResponse(response: response, data: data)
                        cache.storeCachedResponse(cachedData, for: request)
                        DispatchQueue.main.async {
                            self.transition(to: image)
                        }
                    }
                    
                }).resume()
            }
        }
    }
    
    private func transition(to image: UIImage) {
        UIView.transition(with: self, duration: 0.3,
                          options: [.transitionCrossDissolve],
                          animations: { self.image = image },
                          completion: nil)
    }
}

/* With Task API */
extension UIImageView {
    func loadImage(from url: URL?, withImagePlaceholder placeholder: UIImage? = nil, withAnimation animation: Bool = true) {
        image = placeholder
        guard let url = url else { return }
        let cache = URLCache.shared
        let request = URLRequest(url: url)
        
        Task {
            if let data = cache.cachedResponse(for: request)?.data, let image = UIImage(data: data) {
                Task { @MainActor in self.transition(to: image, withAnimation: animation) }
            } else {
                let (data, response) = try await URLSession.shared.data(for: request)
                let cachedData = CachedURLResponse(response: response, data: data)
                cache.storeCachedResponse(cachedData, for: request)
                guard let image = UIImage(data: data) else { return }
                Task { @MainActor in self.transition(to: image, withAnimation: animation) }
            }
        }
    }
    
    private func transition(to image: UIImage, withAnimation animation: Bool) {
        guard animation else {
            self.image = image
            return
        }
        UIView.transition(with: self, duration: 0.3,
                          options: [.transitionCrossDissolve],
                          animations: { self.image = image },
                          completion: nil)
    }
}