How do I use UserDefaults with SwiftUI?

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The approach from caram is in general ok but there are so many problems with the code that SmushyTaco did not get it work. Below you will find an “Out of the Box” working solution.

1. UserDefaults propertyWrapper

import Foundation
import Combine

@propertyWrapper
struct UserDefault<T> {
    let key: String
    let defaultValue: T
    
    init(_ key: String, defaultValue: T) {
        self.key = key
        self.defaultValue = defaultValue
    }
    
    var wrappedValue: T {
        get {
            return UserDefaults.standard.object(forKey: key) as? T ?? defaultValue
        }
        set {
            UserDefaults.standard.set(newValue, forKey: key)
        }
    }
}

2. UserSettings class

final class UserSettings: ObservableObject {

    let objectWillChange = PassthroughSubject<Void, Never>()

    @UserDefault("ShowOnStart", defaultValue: true)
    var showOnStart: Bool {
        willSet {
            objectWillChange.send()
        }
    }
}

3. SwiftUI view

struct ContentView: View {

@ObservedObject var settings = UserSettings()

var body: some View {
    VStack {
        Toggle(isOn: $settings.showOnStart) {
            Text("Show welcome text")
        }
        if settings.showOnStart{
            Text("Welcome")
        }
    }
}

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