Encoding/Decoding not working on Dictionary Objects

I'm not able to repeat your problem. I haven't used archivers before, but here is the code I used. What are you trying to do that is different from what I'm doing?

class MyUserDefinedClass : NSObject {
    let a : Int

    init(a:Int) {
        self.a = a
    }

    @objc required init(coder aDecoder: NSCoder) {
        self.a = aDecoder.decodeObjectForKey("a") as! Int
    }

    @objc func encodeWithCoder(aCoder: NSCoder) {
        aCoder.encodeObject(a, forKey: "a")
    }

    override var description: String {
        return "\(a)"
    }
}

class Foo : NSObject {
    var myDictionary : Dictionary<Int, [MyUserDefinedClass]>!

    override init() {
        myDictionary = [:]
        myDictionary[0] = [MyUserDefinedClass(a:2)]
        myDictionary[1] = [MyUserDefinedClass(a:3)]
    }

    @objc required init(coder aDecoder: NSCoder) {
        self.myDictionary = aDecoder.decodeObjectForKey("myDictionaryObject") as? Dictionary
    }

    @objc func encodeWithCoder(aCoder: NSCoder) {
        aCoder.encodeObject(myDictionary, forKey: "myDictionaryObject")
    }
}

let foo = Foo()

let archived = NSKeyedArchiver.archivedDataWithRootObject(foo)

let foo2 = NSKeyedUnarchiver.unarchiveObjectWithData(archived)

print(foo.myDictionary) // prints [0: [2], 1: [3]]

print(foo2?.myDictionary) // prints Optional([0: [2], 1: [3]])

Thanks for your reply ...

last night I finally determined what was going on. Xcode 6.4 actually gave me a more verbose error message which helped.

It turns out that I was using a struct as the object type in the dictionary. Even though you can implement the NSCoding protocol in a struct, you cannot inherient from NSObject. I changed the object type to a class, inherited NSObject, and updated the misc syntax changes in the protocol, and now everything works fine.

Very odd .. it's things such as this that make using a new language interested 🙂

Again, thanks for your reply.

-gary

A good example of why naming things correctly is so crucial. In your OP you said the dictionary contained "MyUserDefinedClass" when it sounds like it wasn't a class at all. It would be hard for anyone to guess the problem given that misleading bit of info.

Actually it was a Class .. in the class I had two Dictionary Object, each one contained an <key,[Object]> .. it was those objects that were a struct. Sorry that I didn't make that clear.

thanks,

-gary