encapsulating the user code_2.swift

extension ViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
        let image = (info[UIImagePickerControllerEditedImage] as? UIImage) ?? (info[UIImagePickerControllerOriginalImage] as? UIImage)
        if let data = image.flatMap({ UIImageJPEGRepresentation($0, 0.8)} ) {
            api.upload(avatar: data).then { [weak self] in
                self?.avatarView.image = image
                self?.dismiss(animated: true, completion: nil)
            }
            .catch { [weak self] error in
                self?.dismiss(animated: true) {
                    let alert = UIAlertController(title: "Error", message: error.localizedDescription, preferredStyle: .alert)
                    alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
                    self?.present(alert, animated: true, completion: nil)
                }
            }
        }
    }

    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        dismiss(animated: true, completion: nil)
    }
}