boutique-stored-values

Boutique Stored Values

Use this skill when you need to persist individual values (preferences, settings, feature flags) using @StoredValue (backed by UserDefaults) or sensitive data (auth tokens, passwords) using @SecurelyStoredValue (backed by the system Keychain).

Prerequisites

• Boutique added as a dependency via Swift Package Manager.
• Stored values must conform to Codable, Sendable, and Equatable.

@StoredValue (UserDefaults)

Basic declaration

@StoredValue(key: "hasHapticsEnabled")
var hasHapticsEnabled = false

@StoredValue(key: "lastOpenedDate")
var lastOpenedDate: Date? = nil

@StoredValue(key: "currentTheme")
var currentlySelectedTheme: Theme = .light

In @Observable classes

Always pair with @ObservationIgnored to prevent duplicate observation tracking.

@Observable
final class Preferences {
    @ObservationIgnored
    @StoredValue(key: "hasHapticsEnabled")
    var hasHapticsEnabled = false

    @ObservationIgnored
    @StoredValue(key: "lastOpenedDate")
    var lastOpenedDate: Date? = nil

    @ObservationIgnored
    @StoredValue(key: "currentTheme")
    var currentlySelectedTheme: Theme = .light
}

Setting and resetting values

Use the $ projected value to access set and reset.

// Set a new value
$lastOpenedDate.set(.now)
$currentlySelectedTheme.set(.dark)

// Reset to the default value provided at declaration
$lastOpenedDate.reset()          // Back to nil
$currentlySelectedTheme.reset()  // Back to .light

Boolean toggle

$hasHapticsEnabled.toggle()

// Equivalent to:
// $hasHapticsEnabled.set(!hasHapticsEnabled)

Keypath setter (nested property updates)

Update a single property inside a complex stored object without manually copying.

struct UserPreferences: Codable, Sendable, Equatable {
    var hasHapticsEnabled: Bool
    var prefersDarkMode: Bool
    var prefersWideScreen: Bool
}

@ObservationIgnored
@StoredValue(key: "userPreferences")
var preferences = UserPreferences(
    hasHapticsEnabled: true,
    prefersDarkMode: false,
    prefersWideScreen: false
)

// Update a single nested property
$preferences.set(\.prefersDarkMode, to: true)