JSF2.0 - Handling erroneous Ajax calls with Primefaces 3.0

Question

I have a commandButton in my .xhtml page:

Answer 1

onerror calls this function:
onerror(xhr, status, exception) - Javascript callback to process when ajax request fails. Takes three arguments, xmlhttprequest, status string and exception thrown if any.
This info is from documentation. xhr - is actually a request. So there can be found request status and a lot of other info.

<p:commandButton action="#{someone.doSomething()}"
            ajax="true"
            onerror="console.debug(xhr)">
</p:commandButton>

Try this code in chrome or firebug. It will show xhr object

Get a look into http://primefaces.googlecode.com/files/primefaces_users_guide_3_0.pdf section 7.2 Ajax API