onDelete: Accessing Data From Entry Before it is Deleted - ios14

Question

When a user swipes to delete an entry in a list, isn't there a pointer that can be used to get information on the entry being deleted? Before the entry is deleted I want to know the category total. I'm having trouble with the function removeItems which is giving the error: Cannot convert value of type 'IndexSet' to expected argument type 'Int'
struct CatItem: Codable, Identifiable {
var id = UUID()
var catNum: Int
var catName: String
var catTotal: Double
var catPix: String
var catShow: Bool
}
class Categories: ObservableObject {
#Published var catItem: [CatItem] {
didSet {
}
}
}
struct manCatView: View {
#EnvironmentObject var userData: UserData
#EnvironmentObject var categories: Categories
var pic: String = ""
var body: some View {
List {
ForEach(0 ..< categories.catItem.count) { index in
if index.catShow == true {
HStack {
let pic = categories.catItem[index].catPix
Image(systemName: pic)
.resizable()
.foregroundColor(Color(colors[index]))
.frame(width: 40, height: 40)
Text(categories.catItem[index].catName)
}
}
}
.onDelete(perform: removeItems)
}
.navigationBarTitle(Text("Manage Categories"), displayMode: .inline)
NavigationLink(destination: addCatView()) {Text("Add Categories")
.fontWeight(.bold)}
.font(.title2)
.disabled(categories.catItem.count > 16)
.padding([.leading, .trailing], 10)
.accentColor(Color(red: 60/255, green: 160/255, blue: 240/255))
Text("")
Text("")
Text("Add Up to 5 Categories")
Text("Swipe Left to Delete a Category")
Rectangle()
.frame(width: 50, height: 175)
.foregroundColor(.white)
}
func removeItems(at offsets: IndexSet) {
var catTotal: Double = 0.0
//subtract entry amount from category total
catTotal = categories.catItem[offsets].catTotal // <-- need help with index here
userData.totalArray[grandTotal] -= catTotal
userData.totalArray[userTotal] -= catTotal
categories.catItem.remove(atOffsets: offsets)
}
}

Answer 1

IndexSet here is simple Set of Indexies, in simple case it will contain only one element (user delete entries one by one with swipe). So for simplicity you can use .first element for this. But better - to iterate through full set, it'll allow you more control.
so code you need may look similar to this:
func removeItems(at offsets: IndexSet) {
var catTotal: Double = 0.0
offsets.forEach { singleOffset in
//subtract entry amount from category total
catTotal = categories.catItem[singleOffset].catTotal
userData.totalArray[grandTotal] -= catTotal
userData.totalArray[userTotal] -= catTotal
}
categories.catItem.remove(atOffsets: offsets)
}