Conditional display of p:overlayPanel

问题

How can I show/hide the overlay panel conditionally from @ManagedBean based on some result.
In the below code: p:overlayPanel is for p:commandButton. I want to show overlay panel conditionally from Action method.
Right now it is showing every time I click the commandbutton.

<h:form id="form">
    <h:outputLabel value="Town Name:"/>
    <h:inputText value="#{myBean.town}"/>
    <p:commandButton id="checkBtn" value="Check" action="#{myBean.action}"/>

    <p:overlayPanel  widgetVar="overL" id="over" for="checkBtn">
       <h:outputText value="This town is not Listed in our records"/>
    </p:overlayPanel>
</h:form>

Note : I'm using **Primefaces 3.5**

回答1:

Give the overlay panel a widget name and set showEvent to none (this kills the default behavior and assign a javascript handle to the panel):

widgetVar="myOverlay" showEvent="none"

add oncomplete attr to you button, something like:

oncomplete="if(args && !args.validationFailed) myOverlay.show();"

来源：https://stackoverflow.com/questions/18333219/conditional-display-of-poverlaypanel