my json experiments

gistfile1.swift

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

import UIKit

// Data -> JSON?
// JSON -> Cafe?

enum JSONValue {
  case JSONObject([String:JSONValue])
  case JSONArray([JSONValue])
  case JSONString(String)
  case JSONNumber(NSNumber)
  case JSONBool(Bool)
  case JSONNull
  
  var object: [String:JSONValue]? {
    switch self {
    case .JSONObject(let value):
      return value
    default:
      return nil
    }
  }
  
  var array: [JSONValue]? {
    switch self {
    case .JSONArray(let value):
      return value
    default:
      return nil
    }
  }
  
  var string: String? {
    switch self {
    case .JSONString(let value):
      return value
    default:
      return nil
    }
  }
  
  var integer: Int? {
    switch self {
    case .JSONNumber(let value):
      return value.integerValue
    default:
      return nil
    }
  }
  
  var double: Double? {
    switch self {
    case .JSONNumber(let value):
      return value.doubleValue
    default:
      return nil
    }
  }
  
  var bool: Bool? {
    switch self {
    case .JSONBool(let value):
      return value
    case .JSONNumber(let value):
      return value.boolValue
    default:
      return nil
    }
  }
  
  subscript(i: Int) -> JSONValue? {
    get {
      switch self {
      case .JSONArray(let value):
        return value[i]
      default:
        return nil
      }
    }
  }
  
  subscript(key: String) -> JSONValue? {
    get {
      switch self {
      case .JSONObject(let value):
        return value[key]
      default:
        return nil
      }
    }
  }
  
  static func fromObject(object: AnyObject) -> JSONValue? {
    switch object {
    case let value as NSString:
      return .JSONString(value)
    case let value as NSNumber:
      return .JSONNumber(value)
    case let value as NSNull:
      return .JSONNull
    case let value as NSDictionary:
      var jsonObject: [String:JSONValue] = [:]
      for (k: AnyObject, v: AnyObject) in value {
        if let k = k as? NSString {
          if let v = JSONValue.fromObject(v) {
            jsonObject[k] = v
          } else {
            return nil
          }
        }
      }
      return .JSONObject(jsonObject)
    case let value as NSArray:
      var jsonArray: [JSONValue] = []
      for item in value {
        if let item = JSONValue.fromObject(item) {
          jsonArray.append(item)
        } else {
          return nil
        }
      }
      return .JSONArray(jsonArray)
    default:
      return nil
    }
  }
}

protocol JSONSerializable {
  func toJSON() -> JSONValue?
}

protocol JSONDeserializable {
  class func fromJSON(value: JSONValue) -> Self?
}

final class Country: JSONSerializable, JSONDeserializable {
  let name: String
  init(name: String) {
    self.name = name
  }
  
  func toJSON() -> JSONValue? {
    return nil
  }
  
  class func fromJSON(value: JSONValue) -> Country? {
    if let name = value["name"]?.string {
      return Country(name: name)
    }
    return nil
  }
}

final class Cafe: Printable, JSONSerializable, JSONDeserializable {
  let id: Int
  let name: String
  
  var country: Country?
  var city: String?
  var zip: String?
  
  required init(id: Int, name: String) {
    self.id = id
    self.name = name
  }
  
  class func fromJSON(value: JSONValue) -> Cafe? {
    switch (value["id"]?.integer, value["name"]?.string) {
    case (.Some(let id), .Some(let name)):
      let cafe = Cafe(id: id, name: name)
      cafe.city = value["city"]?.string
      
      if let countryJson = value["country"] {
        cafe.country = Country.fromJSON(countryJson)
      }
      
      return cafe
    default:
      return nil
    }
  }

  class func fromJSON2(value: JSONValue) -> Cafe? {
    if let id = value["id"]?.integer {
      if let name = value["name"]?.string {
        let cafe = Cafe(id: id, name: name)
        cafe.city = value["city"]?.string
        
        if let countryJson = value["country"] {
          cafe.country = Country.fromJSON(countryJson)
        }
        
        return cafe
      }
    }
    
    return nil
  }
  
  func toJSON() -> JSONValue? {
    return nil
  }
  
  var description: String {
    get {
      return "<Cafe id:\(id), name: \(name), city: \(city), zip: \(zip), country: \(country)>"
    }
  }
}


let jsonString = "{\"id\":45, \"name\":\"Good Cafe\", \"city\": \"Istanbul\", \"country\": {\"name\": \"Turkei\"} }"
let jsonData = jsonString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)!

var jsonError: NSError?
if let parsed: AnyObject = NSJSONSerialization.JSONObjectWithData(jsonData, options: NSJSONReadingOptions(0),
  error: &jsonError) {
    if let jsonObject = JSONValue.fromObject(parsed) {
      if let cafe = Cafe.fromJSON(jsonObject) {
        println("\(cafe.description)")
      }
      
      //      if let id = jsonObject["id"]?.integer {
      //        println("id is \(id)")
      //      }
    }
}