Steps to Reproduce

https://zkfiddle.org/sample/2k9ik12/1-SimpleConstraint-server-flag-test

type aaa to the first textbox and type bbb to the second textbox, then click the "to server" button.

Current Result

both textbox have same behavior.
no matter the SimpleConstraint.SERVER flag is added or not,
once the client side validation pass, the server side validation will be triggered with next request.

Expected Result

not sure, according to the java doc https://www.zkoss.org/javadoc/9.5.1.3/zk/org/zkoss/zul/SimpleConstraint.html#SERVER

after the client validates the value successfully, it will send the value to the server for further validation.

maybe we should not send it to server validation if the SimpleConstraint.SERVER is not added.

Debug Information

Workaround