It's not null but is it empty?

NilIfEmpty.swift

extension Optional where Wrapped == String {
    var nilIfEmpty: String? {
        guard let strongSelf = self else {
            return nil
        }
        return strongSelf.isEmpty ? nil : strongSelf
    }
}//USAGE
//guard let title = textField.text.nilIfEmpty else {
//    // Alert: textField is empty!
//    return
//}