Swift, Was it possible make ReactiveCocoa work for protocol

Question

I think it's nice if the code was interface drive
so how to make ReactiveCocoa work for protocol in swift? e.g.

protocol SomeBody {
    var name: String { get set }
}
...
class XXViewController {
    @IBOutlet weak var someLabel:UILabel!
    var someOne: SomeBody {
        didSet {
            RACObserve(someOne, "name").subscribeNext { [weak self](name) -> Void in
                self?.someLabel.text = name as! String
            }
        }
    }
   ....
}

Answer 1

RACObserve is built on top of the KVO, so for it to work name needs to be key-value observable. Objects in Swift are not KVO compliant by default.

You can add KVO compliance by inheriting from NSObject:

class Foo : NSObject, SomeBody {
    var name: String = ""
}

Or making individual property observable:

class Foo : SomeBody {
    dynamic var name: String = ""
}

AFAIK, there is no way to enforce this behaviour by protocol definition, only support it in the individual implementations.