SwiftUI: Index out of range when deleting cells with toggle

Question

I have problems with deleting cells that contain a Toggle.

My model looks like this:

class Model: ObservableObject {
    @Published var items: [Item]
    
         


        

Answer 1

A possible solution is to use a default value instead of force-unwrapping. When you delete a row in the list, its ItemCell view may still exist in memory. By using a default value you can prevent crashing (there's no risk of manipulating the wrong item as you can't access this view anymore).

var itemIndex: Int { model.items.firstIndex(where: { $0.id == item.id }) ?? 0 }

Alternatively, you can use an optional index:

struct ItemCell: View {
    @EnvironmentObject var model: Model
    var item: Item
    var itemIndex: Int? { model.items.firstIndex(where: { $0.id == item.id }) }

    var body: some View {
        Group {
            if itemIndex != nil {
                Toggle(isOn: $model.items[itemIndex!].isImportant) {
                    Text(item.text)
                }
            }
        }
    }
}