http://www.zkoss.org/forum/listComment/17372/1/20#reply
http://zkfiddle.org/sample/1cl18gh/1-Require-user-to-enter-uppercase-chars-only-in-textbox

For example , if user only want to allow user enter "1234567890" without ",." ,
currently we could only overwrite the widget.

And it's better if we could use regex to handle this format. (If possible)

This is a FAQ on the forum , and also our customer.
btw , it's better to apply this on Textbox,Decimalbox,Intbox , so maybe we should apply on InputWidget.