CodableExtensionExample.swift

//
//  CodableExtensionExample.swift
//
//  Created by Pramod Kumar on 05/15/20.
//  Copyright © 2020 Swift Commmunity. All rights reserved.
//

import UIKit

let json = """
{
    "body": "It is awesome!",
    "replySent": true,
    "senderName": "Swift Commmunity"
}
"""

struct Message: Codable {
    var body: String
    var replySent: Bool
    let senderName: String
}

func save(message: Message) {
    //Do great things with model object
}

guard let data = json.data(using: .utf8) else {
    fatalError("No able to convert from String to Data")
}

extension Encodable {
    func encoded() throws -> Data {
        return try JSONEncoder().encode(self)
    }
}

extension Data {
    func decoded<T: Decodable>() throws -> T {
        return try JSONDecoder().decode(T.self, from: self)
    }
}

// We can always provide the type, whilst making
// the call site read very nicely.
let messageObj = try data.decoded() as Message

// And if not, the compiler can often infer the
// type from the current context that we want
// to decode. Because we are using generic type
// in the decoded() method.
try save(message: data.decoded())

// We can directly encode our model object to data
let encodedMessage = try messageObj.encoded()