niksativa/storagekit

Key Features

• Type-safe read/write access to stored values
• Reactive integration with Combine for observing value changes
• Support for multiple storage backends:

- UserDefaults - File system - Keychain - In-memory

• Property wrappers for declarative usage
• Support for composable storage layers
• Built-in expiration handling for time-sensitive values

Installation

Swift Package Manager

Add the following to your Package.swift file:

dependencies: [
    .package(url: "https://github.com/NikSativa/StorageKit.git", from: "1.0.0")
]

Usage

Property Wrappers

@Defaults

Property wrapper that provides type-safe access to values persisted in UserDefaults. Supports Codable types:

import StorageKit

struct User: Codable {
    let name: String
    let email: String
    let age: Int
}

final class UserViewModel {
    @Defaults("user")
    var user: User? {
        didSet {
            print("User updated: \(user)")
        }
    }
}

@Expirable

Property wrapper that adds expiration to stored values:

@Expirable(lifetime: .oneHour) var token: String?

Storage Types

UserDefaultsStorage

Persistent storage using UserDefaults:

let storage = UserDefaultsStorage<Int?>(key: "MyKey")
storage.value = 1

FileStorage

Persistent storage using the file system. Supports customizable file paths:

let storage = FileStorage<Int>(fileName: "TestFile.txt")
storage.value = 1

KeychainStorage

Secure storage using the Keychain:

let storage = KeychainStorage(
    key: "MyKey",
    configuration: .init(service: Bundle.main.bundleIdentifier ?? "MyService")
)
storage.value = auth.token

InMemoryStorage

Transient storage using in-memory values:

let storage = InMemoryStorage<Int>(value: 1)
storage.value = 1

Storage Composition

Combine multiple storage layers for advanced scenarios:

// Combine two storages
let combined = inMemoryStorage.combine(userDefaultsStorage)

// Combine multiple storages (iOS 16+)
let combined = zip(storages: [
    InMemoryStorage<Int?>(value: 1),
    UserDefaultsStorage(key: "MyKey")
])

// For non-nil literal types provide explicit defaultValue
let combinedInt = zip(
    storages: [
        InMemoryStorage<Int>(value: 1),
        UserDefaultsStorage<Int>(key: "MyKey", defaultValue: 0)
    ],
    defaultValue: 0
)

Reactive Updates

All storage types provide Combine publishers for observing value changes:

let storage = UserDefaultsStorage<String>(key: "MyKey")
let cancellable = storage.sink { value in
    print("Value updated: \(value)")
}

Requirements

• iOS 13.0+ / macOS 11.0+ / tvOS 13.0+ / watchOS 6.0+ / visionOS 1.0+
• Swift 5.10+
• Xcode 15.0+

License

StorageKit is available under the MIT license. See the LICENSE file for more info.

Package Metadata

Repository: niksativa/storagekit

Default branch: main

README: README.md