Convert from Type to String and vice versa in swift

I have a generic response serializer:

class ResponseArraySerializer<Element: Ball> {

}

Is there any way to convert that to string, so I will store that string in Core Data database, and then to convert back? Typically I use it like this:

let redBallSerializer = ResponseArraySerializer<RedBall>()
requestInfo.responseSerializer = redBallSerializer

So I what to do the same after initialization from a string (so I can initialize the object when I have only string description of the class). Is it possible?

Solution

This SO answer describes how to use a dictionary to map a string to a class.

You can do the same thing with the various strings you store. However, generics are a bit harder to manage.

First, you need to make a Serializer protocol that ResponseArraySerializer conforms to. This protocol will have the required init:

protocol Serializer {
    init()
}

You then have to add a required initializer to the serializer to satisfy the compiler:

required init() {}

Finally, create the mapping as a dictionary:

let serializerMapping: [String: Serializer.Type] = [
    "redBallSerializer":ResponseArraySerializer<RedBall>.self
    "greenBallSerializer":ResponseArraySerializer<GreenBall>.self
]

let serializerKey = "redBallSerializer"
let redBallSerializer = serializerMapping[serializerKey]!.init()

Creating a mapping for just the generic type itself does not seem to work, so you have to store the whole class.