JSON experiments

json-experiments.swift

//: Playground - noun: a place where people can play

import UIKit

class Value<T> {
    private var value: T?
    private let required: Bool
    var isValid: Bool {
        get {
            return !required || value != nil
        }
    }
    var forcedValue: T {
        get {
            return value!
        }
    }
    var optionalValue: T? {
        get {
            return value
        }
    }

    init(required: Bool) {
        self.value = nil;
        self.required = required
    }

    func valueFromDictionary(dictionary: Dictionary<String, AnyObject>, key: String) {
        guard let value = dictionary[key] as? T else {
            return
        }

        self.value = value
    }
}

struct PersonBuilder {
    var name = Value<String>(required: true)
    var age = Value<Int>(required: false)

    var isValid: Bool {
        get {
            return name.isValid && age.isValid
        }
    }
}

struct Person {
    let name: String
    let age: Int?

    init(builder: PersonBuilder) {
        self.name = builder.name.forcedValue
        self.age = builder.age.optionalValue
    }
}

let people = [["Name": "Hugo Tunius"], ["age": 10]]
var parsed: [Person] = []
for person in people {
    var builder = PersonBuilder()
    builder.name.valueFromDictionary(person, key: "Name")
    builder.age.valueFromDictionary(person, key: "Age")

    if builder.isValid {
        parsed.append(Person(builder: builder))
    }
}

parsed