RxSwift replacement shouldChangeCharactersInRange

Question

I want use UITextfield with RxSwift. My goal is allowing/not input character in User keyboard and removing character from copy paste, I need handle UITextfield\'s delegate

Answer 1

You can observe text update and revert it when necessary:

Observable.zip(textfield.rx.text, textfield.rx.text.skip(1))
    .subscribe(onNext: { (old, new) in
        if $invalid {
            textfield.text = old
        }
    })