Remove core data item after being added SwiftUI - swift

Question

Here's my code
Coffee struct and core data NSManaged
import Foundation
import SwiftUI
import Combine
struct CoffeeItem: Identifiable{
var id = UUID()
var title: String
var favorite: Bool
}
extension CoffeeItem {
static func all() -> [CoffeeItem] {
return [
CoffeeItem(title: "Cappuccino", favorite: UserDefaults.standard.bool(forKey: "Cappuccino")),
CoffeeItem(title: "Macchiato", favorite: UserDefaults.standard.bool(forKey: "Macchiato")),
CoffeeItem(title: "Espresso", favorite: UserDefaults.standard.bool(forKey: "Espresso")),
CoffeeItem(title: "Ristretto", favorite: UserDefaults.standard.bool(forKey: "Ristretto"))
]
}
}
.
import CoreData
class CoffeeFavorite: NSManagedObject {
#NSManaged var title: String
}
Main view
struct CoffeeSection: View {
//Core Data
#Environment(\.managedObjectContext) var managedObjectContext
#FetchRequest(entity: CoffeeFavorite.entity(), sortDescriptors: [NSSortDescriptor(key: "title", ascending: true)]) var coffeeFavorite: FetchedResults<CoffeeFavorite>
#State var coffeeItems = CoffeeItem.all()
var body: some View {
List {
ForEach(0 ..< self.coffeeItems.count) { item in
HStack {
Text(self.coffeeItems[item].title)
.fontWeight(.heavy)
.padding()
Spacer()
Image(systemName: self.coffeeItems[item].favorite ? "heart.fill" : "heart")
.padding()
.onTapGesture {
self.addItem(item: self.coffeeItems[item].title)
self.coffeeItems[item].favorite.toggle()
UserDefaults.standard.set(self.coffeeItems[item].favorite, forKey: self.coffeeItems[item].title)
}
}
}
}
}
func addItem(item: String) {
let newItem = CoffeeFavorite(context: managedObjectContext)
newItem.title = item
saveFavorites()
}
func saveFavorites() {
do {
try managedObjectContext.save()
} catch {
print(error)
}
}
}
Favorite view
struct FavoritesList: View {
//Core Data
#Environment(\.managedObjectContext) var managedObjectContext
#FetchRequest(entity: CoffeeFavorite.entity(), sortDescriptors: [NSSortDescriptor(key: "title", ascending: false)]) var coffeeFavorite: FetchedResults<CoffeeFavorite>
var body: some View {
List {
ForEach(coffeeFavorite, id: \.self) { item in
Text(item.title)
}
.onDelete(perform: deleteItem)
}
}
func deleteItem(indexSet: IndexSet) {
let source = indexSet.first!
let favorites = coffeeFavorite[source]
managedObjectContext.delete(favorites)
saveFavorites()
}
func saveFavorites() {
do {
try managedObjectContext.save()
} catch {
print(error)
}
}
}
I have a main view with 4 coffee items and a heart on the right that when is tapped it adds that item title to core data and I can see it in my favorite view. I can delete my core item from the favorite view with .onDelete(perform: ...) but I want to do the same in my main view by tapping the heart so when I toggle it I add and delete that item from core data.
How can I make it work simultaneously on both views??

Answer 1

To delete all items in Core Data that match a predicate:
private func deleteFavorite(title: String) throws {
let request: NSFetchRequest<NSFetchRequestResult> = NSFetchRequest(entityName: "CoffeeFavorite")
request.predicate = NSPredicate(format: "title == %#", title)
try managedObjectContext.execute(NSBatchDeleteRequest(fetchRequest: request))
}