How to fix deleted task being restored in Userdefaultrs - ios

Question

I'm making a TodoList app.
If you swipe a task from the list to delete it and then add a new task, the deleted task will be restored.
Use storyboard and UIKit.
I want to keep it deleted, what should I do? ..
mac 10.15.7
xcode 12.1
import UIKit
class ViewController: UIViewController {
#IBOutlet var tableView: UITableView!
var tasks = [String]()
override func viewDidLoad() {
super.viewDidLoad()
self.title = "リスト"
tableView.delegate = self
tableView.dataSource = self
if !UserDefaults().bool(forKey: "setup") {
UserDefaults().set(true, forKey: "setup")
UserDefaults().set(0, forKey: "count")
}
updateTasks()
}
func updateTasks() {
tasks.removeAll()
guard let count = UserDefaults().value(forKey: "count") as? Int else {
return
}
for x in 0..<count {
if let task = UserDefaults().value(forKey: "task_\(x+1)") as? String {
tasks.append(task)
}
}
tableView.reloadData()
}
#IBAction func didTapAdd() {
let vc = storyboard?.instantiateViewController(identifier: "entry") as! EntryViewController
vc.title = "リストに追加"
vc.update = {
//非同期処理　更新を優先
DispatchQueue.main.async {
self.updateTasks()
}
}
navigationController?.pushViewController(vc, animated: true)
}
}
extension ViewController: UITableViewDelegate {
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
let vc = storyboard?.instantiateViewController(identifier: "task") as! TaskViewController
vc.title = "リストに追加"
vc.task = tasks[indexPath.row]
navigationController?.pushViewController(vc, animated: true)
}
}
extension ViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return tasks.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = tasks[indexPath.row]
return cell
}
//タスクを削除
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
let index = indexPath.row
tasks.remove(at: index)
let userDefaults = UserDefaults.standard
userDefaults.set(tasks, forKey: "tasks")
userDefaults.removeObject(forKey: "tasks")
tableView.reloadData()
}
}
Is remove (at :) different?
import UIKit
class EntryViewController: UIViewController, UITextFieldDelegate {
#IBOutlet var field: UITextField!
var update: (() -> Void)?
override func viewDidLoad() {
super.viewDidLoad()
field.delegate = self
navigationItem.rightBarButtonItem = UIBarButtonItem(title: "保存", style: .done, target: self, action: #selector(saveTask))
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
saveTask()
return true
}
#objc func saveTask() {
guard let text = field.text, !text.isEmpty else {
return
}
guard let count = UserDefaults().value(forKey: "count") as? Int else {
return
}
let newCount = count + 1
UserDefaults().set(newCount, forKey: "count")
UserDefaults().set(text, forKey: "task_\(newCount)")
update?()
navigationController?.popViewController(animated: true)
}
}
How to save UserDefaults?

Answer 1

The problem I see is; in updateTasks function, you get the tasks from UserDefaults by keys as task_1, task_2 etc. But when deleting a specific task, lets say task_2, you are just removing it from tasks array, not deleting it from UserDefaults. So whenever you call updateTasks function, the deleted task re-appears.
In your EntryViewController, change the saveTask function with following:
#objc func saveTask() {
guard let text = field.text, !text.isEmpty else {
return
}
let tasks = UserDefaults.standard.array(forKey: "tasks") as? [String] ?? []
tasks.append(text)
UserDefaults.standard.set(tasks, forKey: "tasks")
update?()
navigationController?.popViewController(animated: true)
}
In your ViewController, change the following functions:
func updateTasks() {
tasks.removeAll()
tasks = UserDefaults.standard.array(forKey: "tasks") as? [String] ?? []
tableView.reloadData()
}
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
tasks.remove(at: indexPath.row)
let userDefaults = UserDefaults.standard
userDefaults.set(tasks, forKey: "tasks")
updateTasks()
}