Data in the TableView are removed (Swift) - ios

Question

Data in the TableView is removed (Swift)
I have a code for my application "Notes".
But sometimes the data from the table is merely deleted .
How can I fix this?
If you scroll the page back, the data will be erased
** I use to save and load data:**
func save() {
UserDefaults.standard.set(myData, forKey: "notes")
UserDefaults.standard.synchronize()
}
func load(){
if let loadData = UserDefaults.standard.value(forKey: "notes") as? [String] {
myData = loadData
table.reloadData()
}
}
ViewController 1
import UIKit
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var table: UITableView!
var myData: [String] = []
var selectedRow: Int = -1
var newRowText:String = ""
var detailView: DetailViewController!
override func viewDidLoad() {
super.viewDidLoad()
load()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
if selectedRow == -1 {
return
}
myData[selectedRow] = newRowText
if newRowText == "" {
myData.remove(at: selectedRow)
}
table.reloadData()
save()
}
#objc func AddNewNotes(){
if table.isEditing{
return
}
let name:String = ""
myData.insert(name, at: 0)
let indexPath: IndexPath = IndexPath(row: 0, section: 0)
table.insertRows(at: [indexPath], with: .automatic)
table.selectRow(at: indexPath, animated: true, scrollPosition: .none)
self.performSegue(withIdentifier: "detail", sender: nil )
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return myData.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell: UITableViewCell = tableView.dequeueReusableCell(withIdentifier: "cell")!
cell.textLabel?.text = myData[indexPath.row]
return cell
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let detailView:DetailViewController = segue.destination as!DetailViewController
selectedRow = table.indexPathForSelectedRow!.row
detailView.masterView = self
detailView.setText(t: myData[selectedRow])
}
}

Answer 1

Since the data source array that you are filling the table view from is myData, it seems that you would need to call your save() method before reloading the table view (table.reloadData()) in the viewWillAppear(_:) life cycle method:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
// ...
save()
myTableView.reloadData()
// ...
}
Also, (obviously) make sure that myData data source contains the saved desired data.
However, I would recommend to save the data before even leaving the second view controller, probably viewWillDisappear(_:) would be a good place to do it; By applying this, there is no need to call save() in the first view controller anymore, all you have to do is to reload the table view. That would be more logical because the first view controller should displays the saved data, but not saving it, it shall be in the second view controller where you are adding data.