Core Data not fetching in table view - ios

Question

My code below is using core data to add entities to a tableview. The problem is that when I hit the button to add a new entry the data is not displayed on the tableview. But if I quit the simulator and re install the app the entity is there. To get the entities displayed I have to enter it then reinstall the app to get the entity displayed.
import UIKit
import CoreData
class ViewController: UIViewController {
#IBOutlet var rot: UITableView!
#IBOutlet var enterName: UITextField!
var people : [NSManagedObject] = []
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
showdata()
}
#IBAction func iDontLikeSchool(_ sender: Any) {
if(enterName.text?.isEmpty)! {
alertmsg(name: "d")
showdata()
} else {
saveData(name: enterName.text!)
}}
func alertmsg(name:String){
let alert = UIAlertController(title: "D", message: "d", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "ok", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
}
func saveData(name: String) {
guard let appDelage = UIApplication.shared.delegate as? AppDelegate else {
return
}
let managedContext = appDelage.persistentContainer.viewContext
let ee = NSEntityDescription.entity(forEntityName: "PersonalInfo", in: managedContext)!
let person = NSManagedObject(entity : ee , insertInto: managedContext)
person.setValue(name, forKey: "userName")
do {
try managedContext.save()
people.append(person)
alertmsg(name: "saved")
enterName.text = ""
}
catch let err as NSError {
print("judo",err)
}
///
}
func showdata() {
guard let appDelage = UIApplication.shared.delegate as? AppDelegate else {
return
}
let managedContext = appDelage.persistentContainer.viewContext
let fetchReuqst = NSFetchRequest<NSManagedObject>(entityName: "PersonalInfo")
do {
people = try managedContext.fetch(fetchReuqst)
if people.count == 0 {
} else {
}}
catch let err as NSError {
print("judo", err)
}
///
}
}
extension ViewController: UITableViewDataSource, UITableViewDelegate{
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = rot.dequeueReusableCell(withIdentifier: "Person")
let personn = people[indexPath.row]
cell?.textLabel?.text = personn.value(forKey: "userName") as? String
return cell!
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return people.count
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
}
}

Answer 1

The reason why the entry doesn't show up is that you don't tell the view that your model has changed so it doesn't refresh itself.
The tableView gets rendered once on viewDidLoad that's why the data is displayed correctly after the view is loaded freshly (after your app restart).
To solve this issue, keep your viewController's tableView as a property (#IBOutlet if you use the Storyboard) and call
tableView.reloadData()
after you changed your data, in your case e.g. at the end of your func showData() like this.
func showdata() {
guard let appDelage = UIApplication.shared.delegate as? AppDelegate else {
return
}
let managedContext = appDelage.persistentContainer.viewContext
let fetchReuqst = NSFetchRequest<NSManagedObject>(entityName: "PersonalInfo")
do {
people = try managedContext.fetch(fetchReuqst)
if people.count == 0 {
//sth
} else {
// sth
}
} catch let err as NSError {
print("judo", err)
}
tableView.reloadData()
}