How can I change a data value with CoreData in SwiftUI? - core-data

Question

Change the value of a data using CoreData and SwiftUI
I'm trying to modify a boolean value isFavorite of a data with a button (heart) on a cell in a list.
Modele data
import Foundation
import CoreData
public class VoitureItem: NSManagedObject, Identifiable {
#NSManaged public var marque: String?
#NSManaged public var modele: String?
#NSManaged public var annee: String?
#NSManaged public var energie: String?
#NSManaged public var kilometrage: String?
#NSManaged public var isFavorite: Bool
}
extension VoitureItem {
static func getAllVoitureItems() -> NSFetchRequest<VoitureItem> {
let request:NSFetchRequest<VoitureItem> = VoitureItem.fetchRequest() as! NSFetchRequest<VoitureItem>
let sortDescriptor = NSSortDescriptor(key: "isFavorite", ascending: false)
request.sortDescriptors = [sortDescriptor]
return request
}
}
I use in my ContentView a managedObjectCOntext and a FetchRequest to show all the data in a List and to create new data.
I would like to know how I can just click on the button change the value of isFavorite in my CoreData.
ContentView() (main view)
struct ContentView: View {
#Environment(\.managedObjectContext) var managedObjectContext
#FetchRequest(fetchRequest: VoitureItem.getAllVoitureItems()) var voitureItems: FetchedResults<VoitureItem>
var body: some View {
NavigationView {
List {//show list of all the data}
}
}
Button on the cell
Button(action: {
//var fav: Bool = false
print("favorite")
//HERE - Change isFavorite in coreData
}) {
if isFavorite {
Image(systemName: "heart.fill")
.foregroundColor(Color.yellow)
} else {
Image(systemName: "heart")
.foregroundColor(Color.gray)
}
}

Answer 1

Something like this should work.
List(voitureItems) { item in
ItemCell(item: $item)
}
...
struct ItemCell: View {
#Binding var item: VoitureItem
var body: some View {
Button(action: {
item.isFavourite.toggle()
}) {
if item.isFavourite {
Image(systemName: "heart.fill")
.foregroundColor(Color.yellow)
} else {
Image(systemName: "heart")
.foregroundColor(Color.gray)
}
}
}
}