Quandry over Text Storage - swiftui

Question

I have an app with a number of categories--some the can be changed by the user and some that can't. The categories that can't be changed are stored currently in an array while categories that the user can change are stored in a class. The problem comes when creating expense entries where the picker needs to show both types of categories.
The other side of the coin is to place all the categories (text strings) in the class. Here the expense entry picker and class storage will work ok, but then there is the problem of preventing the user from deleting the default categories.
I'm guessing that latter option is the better route since it will place all the categories in the picker list. Here is the code for storing the dynamic categories. I suppose I could add some init() code to store the categories that don't change. Not sure exactly how to do that.
struct CatItem: Codable {
var catName: String
var catPix: String
}
class Categories: ObservableObject {
#Published var catItem: [CatItem] {
didSet {
let encoder = JSONEncoder()
if let encoded = try? encoder.encode(catItem) {
UserDefaults.standard.set(encoded, forKey: "workCat")
}
}
}
init() {
if let catItem = UserDefaults.standard.data(forKey: "workCat") {
let decoder = JSONDecoder()
if let decoded = try? decoder.decode([CatItem].self, from: catItem) {
self.catItem = decoded
return
}
}
self.catItem = []
}
}
How would you prevent the user from deleting some of the fixed categories? Usually you have a list with an onDelete statement.
Can you use the index to determine if deleting is allowed? For example don't delete entry if indexSet[index] < 8?
.onDelete { indexSet in
for index in indexSet {
remove entry
}
do {
try viewContext.save()
} catch {
print(error.localizedDescription)
}
}
}

Answer 1

I assume you wanted something like
.onDelete { indexSet in
guard let i = indexSet.first, indexSet[i] < 8 else { return }
// .. other code

Answer 2

I resolved this storage quandary by deciding to store both the permanent and changeable categories in the same class catItem. In the module where the categories may be viewed and where new categories may be added I use a filtered list showing only the categories that may be edited.
This is how the categories are initialized at startup:
let item = CatItem(catName: "name1", catPix: "sf symbol", noShow: true)
self.catItem.append(item)
This is how the categories are displayed in a list:
List {
ForEach(categories.catItem, id: \.catName) { item in
if item.noShow == false {
HStack {
Text(item.catName)
.padding(.horizontal, 10)
Spacer()
Image(systemName: item.catPix).resizable()
.frame(width: 30, height: 30)
}
}
}
.onDelete(perform: removeItems)
}
So if the user can't see the permanent categories in List, then they can't delete them. The user can only delete the categories that they add.
When the user adds new categories the noShow parameter is set to false.
In the picker the categories are not filtered so all categories may be viewed.