h:selectOneMenu's valueChangeListener is invoked on submit of a page

[leelavathic]

Hi

I have with a value change listener and a command button. Please find the code snippet as below.

<a4j:form>
...
<h:selectOneMenu id="status" value="#{mgdBean.status}" valueChangeListener="#{mgdBean.processStatusChange}">
    <a4j:support event="onchange" reRender="mapdMdlPnl" limitToList="true" oncomplete="showModal('#{mgdBean.showMappedVal}')"/>
    <f:selectItem itemValue="ENABLED" itemLabel="Enabled"/>
    <f:selectItem itemValue="DISABLED" itemLabel="Disabled"/>   
</h:selectOneMenu>                
<a4j:commandButton id="addSave"  title="Save"  action="#{mgdBean.savePage}"/>             
...
</a4j:form>

On click of the save button the value change listener, processStatusChange() is invoked then the control goes to savePage() action method the a4j:commandButton.

Can any one tell me why the value change listener is invoked, which is not supposed to happen unlesss I change the value in it?

I am using Richfaces 3.3.1 GA and its deployed in Apache Tomcat 6.0.16.

Regards

Leela

[ilya_shaikovsky]

add a break point to listener method and check oldValue and newValue from event.

[ilya_shaikovsky]

b.t.w. change occurs when you changing the value in select and control lost focus - so using your code you should realise that in case when you changing the select value and hitting the button - two requests will be sent. from the select and from button.

[leelavathic]

Hi Ilya,

Thanks for your response.

In this case am not changing the  select one menu value at all.

Rather am just clicking the command button.

[ilya_shaikovsky]

so you checked values from event?

[leelavathic]

yes,

the new value is ENABLED

old value is null

[ilya_shaikovsky]

This JSF component has no null state. So it's selects the first option by default. But your status property is null. so after the submit component values old and new are not identical and that's why it sends value change event. Check without any richfaces components and the result will be the same. So define some initial value and you will get the event only when it will be actually changed.

[leelavathic]

Hi Ilya

It worked after setting the default value.

Thanks a lot for your support.

Regards

Leela