Disable a4j:support client side

[mtaal]

Hi,
A question, is it possible to disable a4j:support after it has fired once?
I want to achieve the following. On a form I have a number of fields and a save button, the save button should be enabled when something changed on the form. I also need to keep the changed state server side.
For this I am considering using the following a4j:support:

<a4j:support event="onchange" reRender="persistButton"
action="#{formBean.setDataChanged(true)}"/>
However I do not want to fire this support event after something changed anymore as this will for sure cost performance. So after the first change the a4j:support should be disabled, is this possible?

Or should I solve this diffferently?

Thanks!

gr. Martin

[ilya_shaikovsky]

For example you may use onsubmit on support to cancel the request when some flag changed. ;) Hope it helps.

[mtaal]

Thanks this worked, for reference I did this:

<a4j:support event="onchange" reRender="updateButton"
 rendered="#{formBean.editMode}"
 oncomplete="dataChanged = true;"
 onsubmit="if (dataChanged) return false;"
 action="#{formBean.setDataChanged(true)}"
 limitToList="true"
 bypassUpdates="true" ajaxSingle="true" />

gr. Martin