Ajax更新不起作用

Question

Why is the #{uImanager.select} never updated?

<p:panel id="EditDetailsPanel" header="Edit Details">
    <h:panelGrid columns="2" cellpadding="5">
        <h:outputLabel value="Simple :" />
        <h:selectOneMenu value="#{uImanager.select}">
            <f:selectItem itemValue="val1" itemLabel="Coffee1" />
            <f:selectItem itemValue="val2" itemLabel="Coffee2" />
            <f:selectItem itemValue="val3" itemLabel="Coffee3" />                                  
        </h:selectOneMenu>
    </h:panelGrid>
    <p:commandButton value="Submit" update="EditDetailsForm:EditDetailsPanel"/>
    #{uImanager.select}
</p:panel> 

It points to a private String Select; with a getter and setter. It's defined in a session scoped managed bean.

Answer 1

Because your update attribute likely points to an invalid client ID. If you paid attention to the server logs, then you should have seen something like the following from PrimeFaces:

INFO: Cannot find component with identifier "EditDetailsForm:EditDetailsPanel" in view.

As the <p:panel> is inside the same UINamingContainer parent as the <p:commandButton> itself (at least, based on the code which you've posted so far), you can just specify its relative client ID:

<p:commandButton value="Submit" update="EditDetailsPanel"/>

Or if you insist in specifying the absolute client ID, then you need to prefix it with : :

<p:commandButton value="Submit" update=":EditDetailsForm:EditDetailsPanel"/>

Note that this only works if the <h:form> does by itself not have another UINamingContainer parent. Open the page in browser, rightclick and View Source to figure the generated HTML element ID. Finally you need to take that value, prefixed with : .