Restrict NSTextField to only allow numbers

Question

How do I restrict a NSTextfield to allow only numbers/integers? I\'ve found questions like this one, but they didn\'t help!

Answer 1

Here is a Swift version:

override func isPartialStringValid(partialString: String, newEditingString newString: AutoreleasingUnsafeMutablePointer, errorDescription error: AutoreleasingUnsafeMutablePointer) -> Bool {
    if (count(partialString.utf16)) {
        return true
    }

    if (partialString.rangeOfCharacterFromSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet) != nil) {
        NSBeep()
        return false
    }

    return true
}