TextViewExt.kt

fun TextView.onTextChanged(handler: (text: CharSequence) -> Unit): TextWatcher {
    val watcher = object : TextWatcher {
        override fun afterTextChanged(editable: Editable?) {

        }

        override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
        }

        override fun onTextChanged(text: CharSequence?, p1: Int, p2: Int, p3: Int) {
            (text ?: "").let(handler::invoke)
        }

    }
    addTextChangedListener(watcher)
    return watcher
}