SwiftyJSON to implement json string to swift object

Question

How to implement json string mapper swift object?

class User{
      var name:String
      var age:Int
}

Easy way to convert User object to a json string? and convert a json string to User object?

Answer 1

Check out SwiftyJSON doc's about initialization https://github.com/SwiftyJSON/SwiftyJSON#initialization

Basically your only option is to write a method to convert your object into a dictionary and other one that can build your object from dictionary.

Simple example for your two properties User:

class User {
  var name:String
  var age:Int

  init(name: String, age: Int) {
    self.name = name
    self.age = age
  }
}

extension User {
  convenience init(userDict: [String : AnyObject]) {
    let name = userDict["name"] as! String
    let age =  userDict["age"] as! Int
    self.init(name: name, age: age)
  }

  func serialize() -> [String : AnyObject] {
    return ["name": name, "age": age]
  }
}

Then if you want to pass json strings around your app you can check out

NSJSONSerialization.dataWithJSONObject

NSString(data: yourdata, encoding: NSUTF8StringEncoding)

to produce a json string. There is also NSJSONSerialization.JSONObjectWithData to convert your data the other way around.

Hope that helps!

Edit: To return a string containing JSON replace serialize method with following:

    func serialize() -> String? {
      if let data = try? NSJSONSerialization.dataWithJSONObject(["name": name,   "age": age], options: NSJSONWritingOptions(rawValue: 0)) {
      if let s = NSString(data: data, encoding: NSUTF8StringEncoding) {
        return s as String
      }
    }
    return nil
  }

Answer 2

I used to make a SwiftyJSON JSON object by setting the key and value for each variable, but it felt tedious doing it for every class I make and wasn't flexible when you add new variables to it, so I found a better way for Swift 2.0.

With Swift 2.0, they introduced a class called Mirror. By using this, you can iterate through your lets and variables as such:

class User {
    var name:String
    var age:Int

    init(name: String, age: Int) {
        self.name = name
        self.age = age
    }

    var json: JSON {
        get {
            var dict = [String: AnyObject]()
            let mirror = Mirror(reflecting: self)
            for (_, attr) in mirror.children.enumerate() {
                if let property_name = attr.label as String! {
                    dict[property_name] = attr.value as? AnyObject
                }
            }
            return JSON(dict)
        }
    }
}

So, if you want to get a JSON version of your declared variables and values:

let user1 = User(name: "Bob", age: 52)
print(user1.json)

This will get you:

{
    "age" : 52,
    "name" : "Bob"
}

For getting the String, look at this answer:

user1.json.rawString()!