Which is better to be use JSF's Action event or Javascript?

In my application i am enabling and disabling a button according to the value selected by the user from the <h:SelectOneMenu>. I am using a valu开发者_JS百科eChangeListener for the same operation.My doubt is whether it is good to use javascript or the valueChangeListener for better performance.

Rule #1: JavaScript can be disabled.

By the way, the valueChangeListener already won't be fired automatically without a little help of JavaScript. The onchange="submit()" part is JavaScript.

Depends on what you want to do once the value changes. With javascript, the only way to trigger a server side action is to submit() the form via the onchange attribute. This simply submits all information to the backing bean. The valueChangeListener on the other hand gives you more control on the server side (what element changed, what was the old value, what was the new value)