Reload label swift 3 core data - ios

Question

I have an xCode project and I want to reload a label which contain the user score,
here is the code:
#IBOutlet weak var moneyLabel: UILabel!
#IBOutlet weak var imageMoneyMove: UIImageView!
var managedObjextContext:NSManagedObjectContext!
var coreDataMoney = [Money] ()
var money:Int = 0
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
managedObjextContext = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
loadData()
let moneyItem = Money(context: managedObjextContext)
moneyLabel.text! = String(moneyItem.allMoney)
}
func loadData() {
let presentRequest:NSFetchRequest<Money> = Money.fetchRequest()
do {
coreDataMoney = try managedObjextContext.fetch(presentRequest)
} catch {
print("Could not load data from database \(error.localizedDescription)")
}
}
#IBAction func addMoney(_ sender: Any) {
let moneyItem = Money(context: managedObjextContext)
money += 1
moneyItem.allMoney = Float(money)
moneyLabel.text! = String(moneyItem.allMoney)
print(moneyItem.allMoney)
do {
try self.managedObjextContext.save()
self.loadData()
}catch {
print("Could not save data \(error.localizedDescription)")
}
print(moneyItem.allMoney)
}`
I have an Entity called Money and an attribute of type Float and named allMoney. Thank you !

Answer 1

Assuming you have an Entity Money with is supposed to contain a single record I recommend to implement a computed property with custom getter and setter.
I renamed coreDataMoney with money and money with amount
First of all declare variable for the Money object and a lazy instantiated variable for the managed object context.
var money : Money!
lazy var managedObjextContext : NSManagedObjectContext = {
return (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
}()
Declare the variable amount.
The getter checks if the variable money containing the NSManagedObject is nil. If yes, the object is loaded, then the value is returned.
The setter updates the value in the NSManagedObject object, saves the context and updates the label.
var amount : Float {
get {
if money == nil {
loadData()
}
return money.allMoney
}
set {
money.allMoney = newValue
saveContext()
moneyLabel.text! = String(newValue)
}
}
Create a convenience method to save the context.
func saveContext() {
do {
try self.managedObjextContext.save()
} catch {
print("Could not save data \(error.localizedDescription)")
}
}
The loadData() method load the Money object. If the entity is empty create one.
func loadData() {
let presentRequest:NSFetchRequest<Money> = Money.fetchRequest()
do {
let coreDataMoney = try managedObjextContext.fetch(presentRequest)
if coreDataMoney.isEmpty {
let moneyItem = Money(context: managedObjextContext)
money = moneyItem
saveContext()
} else {
money = coreDataMoney.first!
}
} catch {
print("Could not load data from database \(error.localizedDescription)")
}
}
In viewDidLoad get the variable amount to load the data and update the label.
override func viewDidLoad() {
super.viewDidLoad()
moneyLabel.text! = String(amount)
}
Finally in the addMoney method just increment the amount property. The setter logic updates the CoreData stack and the label.
#IBAction func addMoney(_ sender: Any) {
amount += 1.0
}