parsing-json.swift

func decode(data: Data) throws -> User? {
    do {
        let decoder = JSONDecoder()
        let user = try decoder.decode(User.self, from: data)
        return user
    } catch let error {
        print(error)
        return nil
    }
}

func encode(user: User) -> Data? {
    do {
        let encoder = JSONEncoder()
        let data = try encoder.encode(user)
        return data
    } catch let error {
        print(error)
        return nil
    }
}

func loadUser() -> User? {
    guard let fileURL = Bundle.main.url(forResource: "user", withExtension: "json") else {
        print("couldn't find the file")
        return nil
    }
    
    do {
        let content = try Data(contentsOf: fileURL)
        let user = try decode(data: content)
        return user

    } catch let error {
        print(error)
        return nil
    }
}


// We can decode a User from a json document
if let user = loadUser() {
    print(user.name)
    
    for device in user.devices {
        print(device.name)
    }
    
    // We can encode the user
    if let data = encode(user: user) {
        print(data)
    }
}