Hello:
NOTE: I found the error before this could be posted. The entity name in the code was missing an "s"!!!
I am using CoreData with TableView in my application. I have a tutorial that I am using to learn the process but when I run the code it is producing a fatal error. THE APP CRASHES WHEN I CLICK THE SAVE BUTTON.
Please look at the code and the error location to help me in correcting error in the code.
Fatal error: Unexpectedly found nil while unwrapping an Optional value
2019-05-21 17:00:07.684361-0400 CoreDataTableView[5820:1399382] Fatal error: Unexpectedly found nil while unwrapping an Optional value:
// ViewController.swift
// CoreDataTableView
//
// Created by W Lionel Williams on 5/20/19.
// Copyright © 2019 W Lionel Williams. All rights reserved.
//
import UIKit
import CoreData
class ViewController: UIViewController {
var people: [NSManagedObject] = []
@IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
title = "The List"
tableView.register(UITableViewCell.self,
forCellReuseIdentifier: "Cell")
}
@IBAction func addName(_ sender: UIBarButtonItem) {
let alert = UIAlertController(title: "New Name",
message: "Add a new name",
preferredStyle: .alert)
let saveAction = UIAlertAction(title: "Save", style: .default) {
[unowned self] action in
guard let textField = alert.textFields?.first,
let nameToSave = textField.text else {
return
}
self.save(name: nameToSave)
self.tableView.reloadData()
}
let cancelAction = UIAlertAction(title: "Cancel",
style: .cancel)
alert.addTextField()
alert.addAction(saveAction)
alert.addAction(cancelAction)
present(alert, animated: true)
}
func save(name: String) {
guard let appDelegate =
UIApplication.shared.delegate as? AppDelegate else {
return
}
let managedContext =
appDelegate.persistentContainer.viewContext
let entity =
NSEntityDescription.entity(forEntityName: "Person",
in: managedContext)! //Fatal Error Here:
let person = NSManagedObject(entity: entity,
insertInto: managedContext)
person.setValue(name, forKeyPath: "name")
do {
try managedContext.save()
people.append(person)
} catch let error as NSError {
print("Could not save. \(error), \(error.userInfo)")
}
}
}
// MARK: - UITableViewDataSource
extension ViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView,
numberOfRowsInSection section: Int) -> Int {
return people.count
}
func tableView(_ tableView: UITableView,
cellForRowAt indexPath: IndexPath)
-> UITableViewCell {
let person = people[indexPath.row]
let cell =
tableView.dequeueReusableCell(withIdentifier: "Cell",
for: indexPath)
cell.textLabel?.text =
person.value(forKeyPath: "name") as? String
return cell
}
}
