Creating a superclass which will enable custom initialization from Dictionary for its subclasses

What I have done:

I have several model classes, which have a variable number of attributes each. For example:

class A{
    var a1 : String
    var a2 : Int

    init(){...}
}

class B{
    var b1 : String
    var b2 : Int
    var b3 : AnyObject

    init(){...}
}

and so on. To initialize these classes from a Dictionary, I made a custom initializer with a Dictionary parameter and set each of the attributes like this

public class A{
    var a1 : String
    var a2 : Int

    public init(d : Dictionary<String,AnyObject>){
        if let value = d["a1"] as? String {
            a1 = value
        }else{
            a1 = ""
        }

        if let value = d["a2"] as? Int {
            a2 = value
        }else{
            a2 = 0
        }
    }
}

So, basically I am able to initialze the class A like so:

var objectOfClassA : A = A(d:["a1":"str", "a2":10])

If the Dictionary does not have a proper value corresponding to the key attribute of the class, it will just assign a default value to that attribute.

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The problem:

In this implementation, my problem is that I will have to write the init method for each of the model classes that I want to create. My goal is to avoid writing the init method for every model class.

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What I want to achieve:

Instead of writing the init method for each model class , I want to make a super class Model which will give a Dictionary init method like this to all its subclasses. So my Class A will look like this:

class A : Model{
    var a1 : String
    var a2 : Int
}

and still should initialize like before from a Dictionary. Is this possible in Swift?

I tried to use Swift's reflection function to check the properties of the object being initialized, but I was not able to set the property from the dictionary. I guess the properties which can be seen by reflect(self)[1] are read-only. Please advise me on how to implement this type of functionality.