UIImageLoader.swift

extension UIImage {
  func load(image imageName: String) -> UIImage {
    // declare image location
    let imagePath: String = "\(NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0])/\(imageName).png"
    let imageUrl: URL = URL(fileURLWithPath: imagePath)

    // check if the image is stored already
    if FileManager.default.fileExists(atPath: imagePath),
       let imageData: Data = try? Data(contentsOf: imageUrl),
       let image: UIImage = UIImage(data: imageData, scale: UIScreen.main.scale) {
      return image
    }

    // image has not been created yet: create it, store it, return it
    let newImage: UIImage = // create your UIImage here
    try? UIImagePNGRepresentation(newImage)?.write(to: imageUrl)
    return newImage
  }
}

I am wondering if the load method should be static so that you can call UIImage.load(_:).

- func load(image imageName: String) -> UIImage
+ static func load(image imageName: String) -> UIImage