PushVsModal_2 : Base

ViewController.swift

//
//  ViewController.swift
//  PushVsModal
//
//  Created by jay on 2021/11/06.
//

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        
        makeTitle()
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        
        printVCInfo()
    }
    
    @IBAction func pushViewController() {
        let targetViewController = UIViewController.viewControllerFromMainStoryboard(identifier: ViewController.storyboardIdentifier)
        self.navigationController?.pushViewController(targetViewController, animated: true)
    }
    
    @IBAction func popViewController() {
        guard let stackCount = self.navigationController?.viewControllers.count,
              stackCount > 1 else {
            let alert = UIAlertController(title: nil,
                                          message: "더 이상 Pop 동작을\n실행할 수 없습니다.",
                                          preferredStyle: .alert)
            let confirmAction = UIAlertAction(title: "확인",
                                              style: .default,
                                              handler: nil)
            alert.addAction(confirmAction)
            
            self.present(alert, animated: true, completion: nil)
            return
        }
           
        self.navigationController?.popViewController(animated: true)
    }
    
    @IBAction func popToRootViewController() {
        guard let stackCount = self.navigationController?.viewControllers.count,
              stackCount > 1 else {
            let alert = UIAlertController(title: nil,
                                          message: "더 이상 Pop 동작을\n실행할 수 없습니다.",
                                          preferredStyle: .alert)
            let confirmAction = UIAlertAction(title: "확인",
                                              style: .default,
                                              handler: nil)
            alert.addAction(confirmAction)
            
            self.present(alert, animated: true, completion: nil)
            return
        }
           
        self.navigationController?.popToRootViewController(animated: true)
    }
    
    @IBAction func presentViewController() {
        let targetViewController = UIViewController.viewControllerFromMainStoryboard(identifier: ViewController.storyboardIdentifier)
        let navigationController = UINavigationController(rootViewController: targetViewController)
        navigationController.modalPresentationStyle = .fullScreen
        self.present(navigationController, animated: true)
    }
}

// ViewController 의 Title 작성하는 함수
extension UIViewController {
    func makeTitle() {
        var modalDepth = 1
        var currentPresentingViewController: UIViewController? = self.presentingViewController
        while (currentPresentingViewController != nil) {
            modalDepth += 1
            currentPresentingViewController = currentPresentingViewController?.presentingViewController
        }
        
        self.title = "Modal:\(modalDepth)-Navi:\(navigationController?.viewControllers.count ?? 1)"
    }
    
    func printVCInfo() {
        print("------")
        print("[Self] :", title ?? "")
        print("[Self's Navigation VC] :", self.navigationController ?? "")
        print("[Self's Presenting VC] :", self.presentingViewController)
        print("[Parent VC's Presented VC] :", self.presentingViewController?.presentedViewController)
    }
}

// Storyboard 에서 ViewController 를 생성하기 위한 Util 함수들
extension UIViewController {
     static var storyboardIdentifier: String {
         return String(describing: self)
     }
     
     static func viewControllerFromMainStoryboard(identifier: String) -> UIViewController {
         return viewController(storyboardName: "Main", identifiler: identifier)
     }
     
     static func viewController(storyboardName: String, identifiler: String) -> UIViewController {
         let storyboard = UIStoryboard(name: storyboardName, bundle: nil)
         return storyboard.instantiateViewController(identifier: identifiler)
     }
}