UIImagePickerDelegate.swift

extension ViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        let handleImage: (UIImage?) -> () = { (image) in
            self.imageView.image = image
            self.imageView.isHidden = (image == nil)
            if let image = image {
                UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
            }
        }
        if let image = info[.editedImage] as? UIImage {
            handleImage(image)
        }
        else if let image = info[.originalImage] as? UIImage {
            handleImage(image)
        }
        else {
            handleImage(nil)
        }
        dismiss(animated: true, completion: nil)
    }
    
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        dismiss(animated: true, completion: nil)
    }
}