ForEach and SwiftData Model

Question

314 OP

Created Nov ’23

Replies 1

Boosts 0

Participants 2

Hello World ! I have an issue with a ForEach loop and a SwiftData Model

Here is the code :

import Foundation
import SwiftData

@Model
final class Todo {
    var id: UUID
    var content: String
    var isDone: Bool
    var isImportant: Bool
    var sortValue: Int
    
    init(content: String, isDone: Bool, isImportant: Bool) {
        self.id = UUID()
        self.content = content
        self.isDone = isDone
        self.isImportant = isImportant
        if isImportant{
            self.sortValue = 0
        } else {
            self.sortValue = 1
        }
        
    }
    
}

final class Tag {
    var id: UUID
    var content: String
    
    init(content: String) {
        self.id = UUID()
        self.content = content
    }

}

and the content view :

import SwiftUI
import SwiftData

struct AddTodoView: View {
    @Environment(\.modelContext) private var modelContext
    @Environment(\.dismiss) var dismiss
    
    
    @Query private var tags: [Tag]
    @State private var selectedTag: UUID

    
    @State private var content: String = ""
    @State private var isImportant: Bool = false
    
    @State private var showAlert: Bool = false
    @State private var showAchivement: Bool = false
    
    var body: some View {
        
        TextField("Add a Todo", text: $content)
            .padding()
        
        Toggle(isOn: $isImportant) {
            Text("Important Todo")
        }
        .padding()
        
        
        VStack{
            Picker("Tag",  selection: $selectedTag) {
                ForEach(tags, id: \.self){ tag in
                    Text(tag.content)
                }
            }
        }

and here is the issue message :

Referencing initializer 'init(_🆔 content:)' on 'ForEach' requires that 'Tag' conform to 'Hashable'

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Answer 1

ssmith_c OP

Nov ’23

The message tells you the problem. Your type, Tag, does not conform to Hashable. Tell the compiler that Tag should be Hashable:

final class Tag : Hashable {

and then actually conform to it by providing a hashValue property which returns Int. You can probably just use the hashValue of the UUID you already have in your tag, assuming they are all truly unique.

inside Tag:

var hashValue { id.hashValue }

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