UITextField - Get text before editing changed

Question

I set my text field to accept integer only but want to use UITextField inheritance rather than delegate of shouldChangeCharactersInRange.

Is there any way to get text value before editingChanged called as using dropLast() won't work in case the typed-in character is not at the last position.

class TextFieldInteger: UITextField {

    // A character set with number digits only
    let decimalRange = CharacterSet.decimalDigits

    override func awakeFromNib() {
        self.addTarget(self, action: #selector(editingDidBegin), for: .editingDidBegin)
        self.addTarget(self, action: #selector(editingChanged), for: .editingChanged)
    }

    func editingDidBegin() {
        // Remove all existing "," from the input if having any
        input = input.replacingOccurrences(of: ",", with: "")
    }

    func editingChanged() {        
        if input.characters.count > 0 {
            let textSet = CharacterSet(charactersIn: input)
            if !decimalRange.isSuperset(of: textSet) {
                input.dropLast()
            }
        }
    }
}

extension UITextField {
    var input: String {
        get { return text ?? "" }
        set { text = newValue }
    }
}