How do I load images with AsyncImage and caching strategies?

Loading images efficiently in SwiftUI can be achieved using the `AsyncImage` view. This component allows for asynchronous fetching of images and can be paired with caching strategies to enhance performance and reduce network load.

In this example, we'll explore how to use `AsyncImage` along with a simple caching mechanism. The caching can be implemented using a custom `ImageCache` class that stores images in memory.


        import SwiftUI

        // ImageCache Class
        final class ImageCache {
            private var cache = NSCache()
            
            func get(for url: NSURL) -> UIImage? {
                return cache.object(forKey: url)
            }
            
            func store(image: UIImage, for url: NSURL) {
                cache.setObject(image, forKey: url)
            }
        }

        struct AsyncImageView: View {
            @State private var image: UIImage? = nil
            let url: String
            private let cache = ImageCache()

            var body: some View {
                Group {
                    if let image = image {
                        Image(uiImage: image)
                            .resizable()
                            .aspectRatio(contentMode: .fit)
                    } else {
                        ProgressView()
                            .onAppear {
                                loadImage()
                            }
                    }
                }
            }

            private func loadImage() {
                guard let url = URL(string: url) else { return }

                if let cachedImage = cache.get(for: url as NSURL) {
                    image = cachedImage
                } else {
                    URLSession.shared.dataTask(with: url) { data, response, error in
                        guard let data = data, let fetchedImage = UIImage(data: data) else { return }
                        cache.store(image: fetchedImage, for: url as NSURL)
                        DispatchQueue.main.async {
                            image = fetchedImage
                        }
                    }.resume()
                }
            }
        }

AsyncImage SwiftUI caching strategy ImageCache image loading SwiftUI images

How do I load images with AsyncImage and caching strategies?

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How do I load images with AsyncImage and caching strategies?

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