Having two fields of which only one should be used at a time

[zdenek.zikan]

I am RichFaces newbie and I'm trying to achieve following:

I have Entity which is of some EntityType.
User can either
- enter entity ID into edit box and it will show him table with this single entity
or
- select entity type from drop down menu - then it will show him the same table, just with multiple entities of that type.

I JSP it looks like this:

<h:form id="searchForm">
 ...
 Select single entity ID:
 <h:outputLabel for="entityId">ID number</h:outputLabel>
 <h:inputText id="entityId" value="#{dataUpdateBean.entityId}"/>
 <h:commandButton value="Search" type="submit" />
 or select a category
 <h:selectOneMenu value="#{dataUpdateBean.selectedTypeId}">
 <f:selectItems value="#{dataUpdateBean.selectItems}" />
 <a4j:support event="onchange" reRender="searchForm" />
 </h:selectOneMenu>
 ...
 <rich:dataTable>...</rich:dataTable>
</h:form>

However, I need a way how to distinguish whether user entered entityId (in that case, I will also change selectedTypeId to reflect it) or whether he selected some type, so I should use only selectedTypeId and null entityId's value.

Anyone would help me?
Thanks, Zdenek

[ilya_shaikovsky]

check ajax support page at richfaces-demo. second tab labeled dynamic selects.

[zdenek.zikan]

Thanks for reply. You mean I should use the valueChangeListener which is used there? The problem is that if I put valueChangeListener to both entityId input box:

<h:inputText ... valueChangeListener="#{dataUpdateBean.idChanged}"/>

and selectedTypeId drop down menu:

<h:selectOneMenu ... valueChangeListener="#{dataUpdateBean.typeChanged}">

then both of them are called even if I change just one of them. I select different entity type and idChanged and then typeChanged are called. If I change entity id, the same happens.