How can I use my own customID as id for ForEach in indices mode in SwiftUI?

Question

I made a CustomStruct which it makes own customID, I could use this customID as id for ForEach in item mode, then I tried to use my own customID as id for ForEach in indices mode, but it gives error, It says Int has no member of customID, which my all reason of making customID was and is to not using Int as id, but using my own customID. How could I solve this issue?

    struct ContentView: View {
    
    @State var arrayOfCustomStruct: [CustomStruct] = [CustomStruct]()
    
    var body: some View {
        
        Spacer()
        
//        VStack {
//
//            ForEach (arrayOfCustomStruct, id: \.customID) { item in
//
//                Text( String(item.customID) )
//
//            }
//
//        }
        
        
        VStack {
            
            ForEach (arrayOfCustomStruct.indices, id:\.self) { index in // << here I want this happen: ----->  id: \.customID
                
                Text( String(arrayOfCustomStruct[index].customID) )
                
            }
            
        }
        
        Spacer()
        
        HStack {
            
            Spacer()
            
            Button("add new item") {
                
                arrayOfCustomStruct.append( CustomStruct(name: "New Item")   )
                
            }
            
            Spacer()
            
            Button("remove an item") {
                
                if arrayOfCustomStruct.count > 0 {
                    arrayOfCustomStruct.remove(at: arrayOfCustomStruct.count-1 )
                }
                
            }
            
            Spacer()
            
        }.padding()
        
    }
}


struct CustomStruct {
    
    init(name: String) {
        CustomStruct.indexOfId += 1
        self.name = name
    }
    
    private static var indexOfId: UInt64 = 0
    let customID: UInt64 = CustomStruct.indexOfId
    var name: String
    
}

Update: customID in Int has completely deferent personality than customID in CustomStruct! It is NOT perfect as CustomStruct.

    extension Int {

    private static var indexOfId: Int = -1
    var customID: Int {
        
        Int.indexOfId += 1
        return Int.indexOfId
    }
    
}

have you read my title? Custom! UUID is not Custom.

swiftPunk
– swiftPunk

2020-12-18 06:14:29 +00:00
Commented Dec 18, 2020 at 6:14 — swiftPunk
– swiftPunk, Commented Dec 18, 2020 at 6:14

Asperi · Accepted Answer · 2020-12-18 06:05:23Z

1

If you want to have both indices and id by item, you can use enumerated, like

ForEach (Array(arrayOfCustomStruct.enumerated()), id:\.1.customID) { index, item in 
    
    Text( String(arrayOfCustomStruct[index].customID) )
    
}

answered Dec 18, 2020 at 6:05

Asperi

262k28 gold badges594 silver badges889 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

swiftPunk Over a year ago

It is working, but how could I just use index? Here is my idea, let me know if I am wrong or right? When we are just using item mode of ForEach, id goes and find our customID and then it syncing itself to that! But when we use just index mode, ForEach does not access to our customID, because it just care about Range! And Since Range is an Int type it try to go find customID inside of Int to syncing itself! but it can not find it! because customID is property of CustomStruct not Int. Is it right until now?

swiftPunk Over a year ago

with knowing this also that struct cannot inherit from each other, then there is no way using just index mode of ForEach with customID, right?

Asperi Over a year ago

Well... probably you've got stuck with term "mode" - there is no any "mode", ForEach just iterates with collection and use id as a property of element from collection. So when you use arrayOfCustomStruct.indices you don't iterate arrayOfCustomStruct in indices mode, you just iterate over range of Ints, so id can be only that available for Int. (Of course you can add extension to Int with calculable property and use it as ID, but this does not change the sense).

swiftPunk Over a year ago

@ Asperi: U just said all what I said in right syntax, also I just used your advice about extension! Now Int have access to customID. check my Update, it works in index mode as well.

Collectives™ on Stack Overflow

How can I use my own customID as id for ForEach in indices mode in SwiftUI?

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related