URLImage.swift

/**
 Class used to load URL images asynchronously
 */
final class ImageLoader: ObservableObject {
    @Published public var imageData:Data // data that will get published when loaded
    
    init(url imageUrl: String) {
        self.imageData = Data() // assign the value
        
        // call the API and try to get the data
        guard let url = URL(string: imageUrl) else { return } // craete the URL struct
        URLSession.shared.dataTask(with: url) { (data, res, err) in
            if let unwrappedData = data {
                DispatchQueue.main.async {
                    self.imageData = unwrappedData
                }
            }
            
        }.resume()
    }
}

/**
 SwiftUI view that loads an image from a URL asynchronously
 If the image is not available, then the default image is set to Image Unvavailable
 otherwise, the image is updated to contain the image loaded from the URL
 */
struct URLImage: View {
    @ObservedObject var loader: ImageLoader
    
    init(imageUrl: String) {
        loader = ImageLoader(url: imageUrl)
    }
    
    var body: some View {
        Image(uiImage: (loader.imageData.isEmpty ? UIImage(named: "ImageUnavailable")! : UIImage(data: loader.imageData) ?? UIImage(contentsOfFile: "ImageUnavailable")!))
            .resizable()
            .aspectRatio(contentMode: .fit)
    }
}