Added persistent data call and retrival

to-do-list/to-do-list/AppDelegate.swift

@@ -16,6 +16,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
 
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
       // Override point for customization after application launch.
+      Model.shared.loadPersistedListFromDefaults()
       return true
    }
 

to-do-list/to-do-list/DataModel.swift

@@ -9,23 +9,76 @@
 import Foundation
 import UIKit
 
+class Model {
+   static let shared = Model()
+   private init() {}
+
+   let key = "todoList"
+
+   func persistListToDefaults() {
+      let data = NSKeyedArchiver.archivedData(withRootObject: lists)
+      UserDefaults.standard.set(data, forKey: key)
+   }
+
+   func loadPersistedListFromDefaults() {
+      if let data = UserDefaults.standard.object(forKey: key) as? Data {
+         let listOfItems = NSKeyedUnarchiver.unarchiveObject(with: data) as! [List]
+         lists = listOfItems
+      }
+   }
+}
+
 var lists = [List]()
 
-class List {
+class List: NSObject, NSCoding {
+
+   private struct Keys {
+      static let listTitle = "listTittle"
+      static let items = "items"
+   }
+
    var listTitle: String
    var items = [Item]()
 
    init(listTitle: String) {
       self.listTitle = listTitle
    }
+
+   required init?(coder aDecoder: NSCoder) {
+      listTitle = aDecoder.decodeObject(forKey: Keys.listTitle) as! String
+      items = aDecoder.decodeObject(forKey: Keys.items) as! [Item]
+   }
+
+   func encode(with aCoder: NSCoder) {
+      aCoder.encode(listTitle, forKey: Keys.listTitle)
+      aCoder.encode(items, forKey: Keys.items)
+   }
 }
 
-class Item {
+class Item: NSObject, NSCoding {
+
+   private struct Keys {
+      static let itemTitle = "itemTitle"
+      static let description1 = "description1"
+   }
+
    var itemTitle: String
-   var description = "static"
+   var description1 = "description"
 
-   init(itemTitle: String, description: String) {
+   init(itemTitle: String, description1: String) {
       self.itemTitle = itemTitle
-      self.description = description
+      self.description1 = description1
+   }
+
+   required convenience init?(coder aDecoder: NSCoder) {
+      self.init(
+         itemTitle: aDecoder.decodeObject(forKey: Keys.itemTitle) as! String,
+         description1: aDecoder.decodeObject(forKey: Keys.description1) as! String
+      )
+   }
+
+   func encode(with aCoder: NSCoder) {
+      aCoder.encode(itemTitle, forKey: Keys.itemTitle)
+      aCoder.encode(description1, forKey: Keys.description1)
    }
 }

to-do-list/to-do-list/DetailViewController.swift

@@ -28,8 +28,9 @@ class DetailViewController: UIViewController {
 
    // Saves description and displays it on the page
    @IBAction func tappedSaveBtnAction(_ sender: Any) {
-      lists[currentListIndex].items[currentItemIndex].description = yourDescriptionTextFieldOutlet.text!
+      lists[currentListIndex].items[currentItemIndex].description1 = yourDescriptionTextFieldOutlet.text!
       yourDescriptionTextFieldOutlet.backgroundColor = UIColor.clear
+      Model.shared.persistListToDefaults()
    }
 
    // MARK: override ----------------------------------------------------------------------------------------
@@ -39,6 +40,6 @@ class DetailViewController: UIViewController {
       super.viewDidLoad()
       yourListOutlet.text = lists[currentListIndex].listTitle.uppercased()
       yourItemOutlet.text = lists[currentListIndex].items[currentItemIndex].itemTitle
-      yourDescriptionTextFieldOutlet.text = lists[currentListIndex].items[currentItemIndex].description
+      yourDescriptionTextFieldOutlet.text = lists[currentListIndex].items[currentItemIndex].description1
    }
 }

to-do-list/to-do-list/ItemViewController.swift

@@ -38,6 +38,7 @@ class ItemViewController: UIViewController, UITableViewDataSource, UITableViewDe
    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
       if editingStyle == .delete {
          lists[currentItemIndex].items.remove(at: indexPath.row)
+         Model.shared.persistListToDefaults()
          ItemTableOutlet.reloadData()
       }
    }
@@ -50,8 +51,9 @@ class ItemViewController: UIViewController, UITableViewDataSource, UITableViewDe
       // It clears the input field
       ItemTextFieldOutlet.text = ""
       // Creates an instance of List object and appends new item to the lists array
-      lists[currentItemIndex].items.append(Item.init(itemTitle: itemTextField, description: ""))
+      lists[currentItemIndex].items.append(Item.init(itemTitle: itemTextField, description1: ""))
       // reloads the table so that it gets new info
+      Model.shared.persistListToDefaults()
       ItemTableOutlet.reloadData()
    }
 

to-do-list/to-do-list/ListViewController.swift

@@ -35,6 +35,7 @@ class ListViewController: UIViewController, UITableViewDataSource, UITableViewDe
    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
       if editingStyle == .delete {
          lists.remove(at: indexPath.row)
+         Model.shared.persistListToDefaults()
          ListTableOutlet.reloadData()
       }
    }
@@ -49,6 +50,7 @@ class ListViewController: UIViewController, UITableViewDataSource, UITableViewDe
       // Creates an instance of List object and appends new item to the lists array
       lists.append(List.init(listTitle: listTextField))
       // reloads the table so that it gets new info
+      Model.shared.persistListToDefaults()
       ListTableOutlet.reloadData()
    }
 
@@ -65,5 +67,13 @@ class ListViewController: UIViewController, UITableViewDataSource, UITableViewDe
    override func viewWillAppear(_ animated: Bool) {
       ListTableOutlet.reloadData()
    }
+
+   override func viewDidLoad() {
+      super.viewDidLoad()
+
+
+
+   }
+
 }