AntonBelousov / UserDefaultPropertyWrapper

A lightweight library that allows you to use ANY type with UserDefaults

UserDefaultPropertyWrapper

Installation

Add to Podfile:

use_frameworks!
pod 'UserDefaultPropertyWrapper', :git => 'https://github.com/AntonBelousov/UserDefaultPropertyWrapper'

Call pod install

Features

• You can use wrapper with base types: Bool, Int, Double, Float, String, Date, Data. You can use Array of any mentioned type (array of arrays as well), and Dictionary, where Key == String and Value == any mentioned type

• Type may be optional

• You can use custom types, just make your type conform to the UserDefaultsConvertible protocol.

• Some types has predefined default values: false to Bool, 0 for Int, Float, Double, nil for Optional, empty collection for Array and Dictionary. You can specify default values for other types (see UserDefaultsConvertibleWithDefaultValue)

TODO

• Add model version update handling

Usage

import UserDefaultPropertyWrapper

class Settings {
    static let shared = Settings()
    
    @UserDefault("boolValue")
    var boolValue: Bool

    @UserDefault("boolValueWithDefaultValue", defaultValue: true)
    var boolValueWithDefaultValue: Bool
    
    @UserDefault("intValue")
    var intValue: Int

    @UserDefault("intValueWithDefaultValue", defaultValue: 451)
    var intValueWithDefaultValue: Int
    
    @UserDefault("doubleValue")
    var doubleValue: Double
    
    @UserDefault("floatValue")
    var floatValue: Float
    
    @UserDefault("stringValue", defaultValue: "")
    var stringValue: String
    
    @UserDefault("optionalStringValue")
    var optionalStringValue: String?
    
    @UserDefault("dateValue", defaultValue: .distantFuture)
    var dateValue: Date
    
    @UserDefault("optionalDataValue")
    var optionalDataValue: Data?
    
    @UserDefault("array", defaultValue: [1,9,6,1])
    var array: [Int]
    
    @UserDefault("arrayOfArray")
    var arrayOfArray: [[Int]]
    
    @UserDefault("dict")
    var dict: [String: Int]
}

// Than use these properties as usual 

Settings.shared.optionalStringValue = "Some value"
print(String.shared.optionalStringValue)

Settings.shared.optionalStringValue = nil
print(String.shared.optionalStringValue)

Custom types

You can make any type conform to the UserDefaultsConvertible protocol

enum Activity: UserDefaultsConvertible {
    var userDefaultsValue: Any {
        switch self {
        case .reading(let book):
            return "r\(book)"
        case .watching(let movie):
            return "w\(movie)"
        }
    }
    
    static func create(from userDefaultsValue: Any) -> Activity {
        var value = userDefaultsValue as! String
        if value.hasPrefix("r") {
            value.removeFirst()
            return .reading(book: value)
        } else if value.hasPrefix("w") {
            value.removeFirst()
            return .watching(movie: value)
        }
        fatalError()
    }
    
    case watching(movie: String)
    case reading(book: String)
}

class ActivityStorage {
    @UserDefault("activity", defaultValue: nil)
    var activity: Activity?
}

ActivityStorage().activity = .reading(book: "Hearts of Three")
print(ActivityStorage().activity ?? "nil")

Using Codable

If your type conforms to the Codable protocol, you can easily make if conform UserDefaultsConvertible. Just add UserDefaultsConvertible after type name and it will became convertible automatically:

struct User: Codable, UserDefaultsConvertible {
    var firstname: String
    var lastname: String
    var birthdate: Date
    var address: String
}

Custom user defaults

Note. You can use UserDefauls to share data between your application and app extension see

struct User: Codable, UserDefaultsConvertible {
    var firstname: String
    var lastname: String
    var birthdate: Date
    var address: String
}

class UsersSource {
    
    static let defaults = UserDefaults(suiteName: "app.group.id")!
    
    @UserDefault("users", defaultValue:[], defaults: UsersSource.defaults)
    var users: [User]
}

func someMethodInApp() {

    let user = User(
        firstname: "Artur",
        lastname: "Fleck",
        birthdate: Date(timeIntervalSince1970: -729345600),
        address: "Arkham Asylum, Gotham County, New Jersey, United States of America")
    
    var source = UsersSource()
    source.users.append(user)
}

func someMethodInExtension() {
    source = UsersSource()
    print(source.users)
}