firebase - Retrieve String value from function with closure in Swift

Question

I am trying to retrieve a string value from Firebase in order to get each username with an unique UID that is passed to the function, which returns the username of the user. However - since the firebase ObserveEvent is in closures, I can't return any value back because the actions happens asynchronous(?). I was wondering if it was a way of accomplishing this?

The function looks like this:

func GetUsername(uid:String) -> String {
    var username = String()
    firebase.child("Users").child(uid).observeSingleEventOfType(.Value) { (snapshot:FIRDataSnapshot) in

        username = snapshot.value!["Username"] as! String

    }

    return username
}

Obviously this doesn't work, but I want to be able to get the data by doing a GetUsername("whatevertheidmightbe"). Ideas?

Answer 1

Waitting for answers