Automatic JSON serialization and deserialization of objects in Swift

Question

I'm looking for a way to automatically serialize and deserialize class instances in Swift. Let's assume we have defined the following class …

class Person {     let firstName: String     let lastName: String      init(firstName: String, lastName: String) {         self.firstName = firstName         self.lastName = lastName     } } 

… and Person instance:

let person = Person(firstName: "John", lastName: "Doe") 

The JSON representation of person would be the following:

{     "firstName": "John",     "lastName": "Doe" } 

Now, here are my questions:

1. How can I serialize the person instance and get the above JSON without having to manually add all properties of the class to a dictionary which gets turned into JSON?
2. How can I deserialize the above JSON and get back an instantiated object that is statically typed to be of type Person? Again, I don't want to map the properties manually.

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Here's how you'd do that in C# using Json.NET:

var person = new Person("John", "Doe"); string json = JsonConvert.SerializeObject(person); // {"firstName":"John","lastName":"Doe"}  Person deserializedPerson = JsonConvert.DeserializeObject<Person>(json); 

Answer 1

As shown in WWDC2017 @ 24:48 (Swift 4), we will be able to use the Codable protocol. Example

public struct Person : Codable {    public let firstName:String    public let lastName:String    public let location:Location } 

To serialize

let payload: Data = try JSONEncoder().encode(person) 

To deserialize

let anotherPerson = try JSONDecoder().decode(Person.self, from: payload) 

Note that all properties must conform to the Codable protocol.

An alternative can be JSONCodable which is used by Swagger's code generator.