Save and load structs and struct arrays in UserDefaults

UserDefaultsAndStructsExtension.swift

import Foundation

extension UserDefaults {
    open func setStruct<T: Codable>(_ value: T?, forKey defaultName: String){
        let data = try? JSONEncoder().encode(value)
        set(data, forKey: defaultName)
    }
    
    open func structData<T>(_ type: T.Type, forKey defaultName: String) -> T? where T : Decodable {
        guard let encodedData = data(forKey: defaultName) else {
            return nil
        }
        
        return try! JSONDecoder().decode(type, from: encodedData)
    }
    
    open func setStructArray<T: Codable>(_ value: [T], forKey defaultName: String){
        let data = value.map { try? JSONEncoder().encode($0) }
        
        set(data, forKey: defaultName)
    }
    
    open func structArrayData<T>(_ type: T.Type, forKey defaultName: String) -> [T] where T : Decodable {
        guard let encodedData = array(forKey: defaultName) as? [Data] else {
            return []
        }
        
        return encodedData.map { try! JSONDecoder().decode(type, from: $0) }
    }
}

// Example

struct Pizza: Codable {
    let name: String
    let price: Double
}

// struct array exmaple
let allPizzasKey = "ALL_PIZZAS"
UserDefaults.standard.setStructArray([Pizza(name: "Seafood", price: 6.00), Pizza(name: "Crudo", price: 5.50), Pizza(name: "Margherita", price: 3.50)], forKey: allPizzasKey)
let pizzas: [Pizza] = UserDefaults.standard.structArrayData(Pizza.self, forKey: allPizzasKey)
print("All pizzas: \(pizzas)")

// struct exampl
let myFavPizzaKey = "MY_FAV_PIZZA"
UserDefaults.standard.setStruct(Pizza(name: "Seafood", price: 6.00), forKey: myFavPizzaKey)
if let myFavPizza = UserDefaults.standard.structData(Pizza.self, forKey: myFavPizzaKey) {
    print("My fav pizza: \(myFavPizza)")
}