How to serialize or convert Swift objects to JSON?

Question

This below class

class User: NSManagedObject {
  @NSManaged var id: Int
  @NSManaged var name: String
}

Needs to be converted to

Answer 1

I worked a bit on a smaller solution that doesn't require inheritance. But it hasn't been tested much. It's pretty ugly atm.

https://github.com/peheje/JsonSerializerSwift

You can pass it into a playground to test it. E.g. following class structure:

//Test nonsense data
class Nutrient {
    var name = "VitaminD"
    var amountUg = 4.2

    var intArray = [1, 5, 9]
    var stringArray = ["nutrients", "are", "important"]
}

class Fruit {
    var name: String = "Apple"
    var color: String? = nil
    var weight: Double = 2.1
    var diameter: Float = 4.3
    var radius: Double? = nil
    var isDelicious: Bool = true
    var isRound: Bool? = nil
    var nullString: String? = nil
    var date = NSDate()

    var optionalIntArray: Array = [1, 5, 3, 4, nil, 6]
    var doubleArray: Array = [nil, 2.2, 3.3, 4.4]
    var stringArray: Array = ["one", "two", "three", "four"]
    var optionalArray: Array = [2, 4, 1]

    var nutrient = Nutrient()
}

var fruit = Fruit()
var json = JSONSerializer.toJson(fruit)

print(json)

prints

{"name": "Apple", "color": null, "weight": 2.1, "diameter": 4.3, "radius": null, "isDelicious": true, "isRound": null, "nullString": null, "date": "2015-06-19 22:39:20 +0000", "optionalIntArray": [1, 5, 3, 4, null, 6], "doubleArray": [null, 2.2, 3.3, 4.4], "stringArray": ["one", "two", "three", "four"], "optionalArray": [2, 4, 1], "nutrient": {"name": "VitaminD", "amountUg": 4.2, "intArray": [1, 5, 9], "stringArray": ["nutrients", "are", "important"]}}