an example of how to create an async promise task

PromiseTaskExample.swift

func getUserData(#token: String) -> Promise<User>{
    return Promise<User>{ fulfill, reject in
        let task = NSURLSession.sharedSession().dataTaskWithURL(self.getCurrentUserURL){ data , res , err in
            if let err = err{
                return reject(err)
            }
            let user = User(data: data)
            return fulfill(user)
        }
        task.resume()
    }
}