Chapter 8

What we will do:

1. implement messages about shot coordinates, results etc. as well as use user choice from settings how hit information should be displayed - hit or miss only or full;
2. implement autosave and continue last game;
3. add a launch screen (splash screen) - static screen displayed during application start. From May 2020 this I a required component if you want to submit your app to AppStore;
4. add localization - show how to add Polish translation for English strings used so far.

Details for each step:

1. Download source code for this chapter (download source code).
2. About 1
   This steps needs some changes in EngineGameBattleship. Some of them are in Board.swift file
   
   Swift

   private func afterHitAction(row: Int, col: Int) -> (result: EngineGameBattleship.ShotResult, ship: Ship)? func shot(row: Int, col: Int) -> (result: EngineGameBattleship.ShotResult, ship: Ship)?

   1 2	private func afterHitAction(row: Int, col: Int) -> (result: EngineGameBattleship.ShotResult, ship: Ship)? func shot(row: Int, col: Int) -> (result: EngineGameBattleship.ShotResult, ship: Ship)?

   
   and EngineGameBattleship.swift
   
   Swift

   func shot(who: Who, row: Int, col: Int) -> (result: EngineGameBattleship.ShotResult, ship: Ship?)

   1	func shot(who: Who, row: Int, col: Int) -> (result: EngineGameBattleship.ShotResult, ship: Ship?)

   
   but check carefully what has beed changed. Of course some changes are also in GameBattleshipIOS part.

   When implemented, results should be as in this film (download video).

3. About 2
   Add an outlet for "Continue last game" button (download video).

   We use, as before for saving information about ship sets, game definitions (both in previous tutorial), and settings (just before) a Codable protocol but this time it needs some customization as we want to save data being of enum typy which does not conform Codable protocol. So me must take some actions to fix this.

   Please read about this here:

   • NSCoding Tutorial for iOS: How to Permanently Save App Data
   • Encoding and Decoding in Swift
   • Codable enums in Swift

   Changes are mede (mostly) in:

   • Ship (start analyzing from this as the most embedded and the easiest)
   • Ships - only minor changes and conforms automaticaly when Ship conforms
   • Boards - copy approach from Ship

   Then we need to save also information about whose turn was as last. Because it is a smal amount of data, we will use UserDefaults. For explanation , please refer to:

   • How to save user settings using UserDefaults
   • UserDefaults iOS Tutorial
   • Short summary in: How can I use UserDefaults in Swift?
   • UserDefaults in Swift 5.1

   More complete tutorial about saving data in games

   • How to Save your Game’s Data: Part 1/2
   • How to Save your Game’s Data: Part 2/2

   Data storing options summary

   • iOS Data Persistence in Swift

   Nice introduction to CoreData (you may think of this like an internal, built-in database)

   • Getting Started with Core Data Tutorial

   You may also find useful this:

   • Saving Data in iOS Part 1
   • Saving Data in iOS Part 2

   If you are interested in secure save data you may read about some concepts here (an outdated text but main concepts remains)

   • Basic Security in iOS 5 – Part 1

   I made some decision where, in my opinion, is the best place to put the call to game state saving code: look into SceneDelegate.swift and

   Swift

   func sceneWillResignActive(_ scene: UIScene) { // Called when the scene will move from an active state to an inactive state. // This may occur due to temporary interruptions (ex. an incoming phone call). }

   1 2 3 4

   func sceneWillResignActive(_ scene: UIScene) {         // Called when the scene will move from an active state to an inactive state.         // This may occur due to temporary interruptions (ex. an incoming phone call).     }

   We will not use

   Swift

   func sceneDidBecomeActive(_ scene: UIScene) { // Called when the scene has moved from an inactive state to an active state. // Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive. }

   1 2 3 4

   func sceneDidBecomeActive(_ scene: UIScene) {         // Called when the scene has moved from an inactive state to an active state.         // Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.     }

   It would be good if you will read some material related to iOS lifecycle and make your own choice:

   • iOS App Life Cycle
   • Managing Your App's Life Cycle
   • iOS App Lifecycle
   • applicationWillTerminate(_:)

   When all done in this step, results should be as in this film (download video)

4. About 3
   Watch video and repeat in your project all the steps (download video).

   You may also want to read these materials

   • Human Interface Guidelines. Launch Screen
   • iOS Launch Screen (Splash Screen)
5. About 4
   Watch video and repeat in your project all the steps (download video).