coreData not displaying on collection view cell (swift4) - ios

Question

This code right here display a array on a collection view. It works exactly how I want it to.
import UIKit
import CoreData
class collectionVIEW: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource{
var sam = ["3","j"]
var users = [User]()
#IBOutlet var theIssues: UICollectionView!
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return sam.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! whyCollectionViewCell
// cell.general.text = users[indexPath.row].userName
cell.general.text = sam[indexPath.row]
return cell
}
}
In my 2nd code. The code is slightly alerted to call core data and display on the cells. As you can see in the photo there are no cells visible. All I want to do is have the core data be displayed exactly how I was able to do in the first code set.
import UIKit
import CoreData
class collectionVIEW: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource{
var sam = ["3","j"]
var users = [User]()
#IBOutlet var theIssues: UICollectionView!
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return users.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! whyCollectionViewCell
cell.general.text = users[indexPath.row].userName
// cell.general.text = sam[indexPath.row]
return cell
}
}
CORE DATA
import UIKit
import CoreData
class cdHandler: NSObject {
private class func getContext() -> NSManagedObjectContext {
let appdeleagetzz = UIApplication.shared.delegate as! AppDelegate
return appdeleagetzz.persistentContainer.viewContext
}
class func saveObject(userName: String) -> Bool {
let context = getContext()
let entity = NSEntityDescription.entity(forEntityName: "User", in: context)
let managedObject = NSManagedObject(entity: entity!, insertInto: context)
managedObject.setValue(userName, forKey: "userName")
do {
try context.save()
return true
} catch {
return false
}
}
class func fetchObject() -> [User]? {
let context = getContext()
var users: [User]? = nil
do {
users = try context.fetch(User.fetchRequest())
return users
} catch {
return users
}
}
}

Answer 1

First of all do not return an optional in fetchObject(), return an empty array on failure:
class func fetchObject() -> [User] {
do {
let context = getContext()
return try context.fetch(User.fetchRequest())
} catch {
return [User]()
}
}
Second of all, to answer the question, you have to call fetchObject() in viewDidLoad to load the data
func viewDidLoad() {
super.viewDidLoad()
users = cdHandler.fetchObject()
theIssues.reloadData()
}
Note: Please conform to the naming convention that class names start with a capital letter.