encapsulating the user code_5.swift

class ViewController: UIViewController
{
    @IBAction func changeAvatar(_ sender: UITapGestureRecognizer) {
        guard let senderView = sender.view else { fatalError("Tapped on viewless gesture recognizer?") }
        let controller = UIImagePickerController()
        controller.delegate = self
        choiceIndexUsingActionSheet(title: "", message: "", choices: sourceOptions.map { $0.title }, onSourceView: senderView).then { index in
            sourceOptions[index].action(controller)
            self.present(controller, animated: true, completion: nil)
        }
    }
}

typealias ImagePickerAction = (UIImagePickerController) -> Void

private let sourceOptions = { () -> [(title: String, action: ImagePickerAction)] in
    var result = [(title: String, action: ImagePickerAction)]()
    if UIImagePickerController.isSourceTypeAvailable(.camera) {
        result.append(("Camera", { $0.sourceType = .camera }))
    }
    if UIImagePickerController.isSourceTypeAvailable(.photoLibrary) {
        result.append(("Photos", { $0.sourceType = .photoLibrary }))
    }
    return result
}()