Simple Apple MVC file

mvc.swift

import UIKit
import Foundation

class mvcViewController: UIViewController {
  
  private var photos: Photos?
  
  //MARK: View cycle handling
  override func viewDidLoad() {
    label.text = "Something"
  }

  override func viewWillAppear(_ animated: Bool) {
    photos = API.fetchPhotos()
  }
  
  override func viewDidAppear(_ animated: Bool) {
    populateViewWithNewContent()
  }
  
  // MARK: Routing
  override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    guard let photos = photos else { return }
    doSomethingWithPhotos()
  }
  
  // MARK: Actions
  @IBOutlet private weak var photoButton: UIButton!
  @IBAction func pressedPhotoButton(_ sender: Any) {
    API.addPhoto()
    disableButton(photoButton)
  }
  
  //MARK: UI Handling
  private func disableButton(_ button: UIButton) {
    button.isEnabled = false
  }
 
  @IBOutlet private weak var label: UILabel!
  private func populateViewWithNewContent() {
    guard let photos = photos else { return }
    label.text = "Something"
  }
}