generic-codable-decoder.swift

import Foundation

//
// MODEL
//

public struct Show: Codable {
    public var name: String
    public var network: String
}

public struct Season: Codable {
    public var seasonNumber: Int
    public var year: Int
}

public struct Episode: Codable {
    public var title: String
    public var runtime: Int
}

//
// FUNCTION
// 

func decode<T: Codable>(_ type: T.Type, from string: String) -> T? {
    let decoder = JSONDecoder()
    
    if let data = string.data(using: .utf8), let object = try? decoder.decode(type, from: data) {
        return object
    }
    
    return nil
}

//
// DATA
//

let jsonShow = """
{
    "name" : "House of Cards",
    "network" : "Netflix"
}
"""

let jsonSeason = """
{
    "seasonNumber" : 1,
    "year" : 2013
}
"""

let jsonEpisode = """
{
    "title" : "Pilot",
    "runtime" : 52
}
"""

let jsonShows = """
[
    {
        "name" : "House of Cards",
        "network" : "Netflix"
    },
    {
        "name" : "The Big Bang Theory",
        "network" : "CBS"
    }
]
"""

//
// EXAMPLE
//

if let show = decode(Show.self, from: jsonShow) {
    print(show)
}

if let season = decode(Season.self, from: jsonSeason) {
    print(season)
}

if let episode = decode(Episode.self, from: jsonEpisode) {
    print(episode)
}

if let shows = decode([Show].self, from: jsonShows) {
    print(shows)
}

Cool...