This is how I am doing this in swift.
extension String {
func encodeURIComponent() -> String {
return self.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())!
}
func decodeURIComponent() -> String {
return self.componentsSeparatedByString("+").joinWithSeparator(" ").stringByRemovingPercentEncoding!
}
}