Question

I have a Primefaces-based application, in which there are some lengthy operations.

When such operation is being executed, I want to indicate this somehow (like displaying an hourglass or a message, which appears at the center of the screen).

What is the easiest way to do this in Primefaces/JSF?

Answer 1

I’d recommend doing it with <p:blockUI>. Here’s an example:

<h:form>
    <p:panel id="content" >
        ...
        <p:commandButton id="longOperation" value="Process" />
    </p:panel>
    <p:blockUI block="content" trigger="longOperation">  
        <p>Here you can customize what appears as the overlay over the blocked content.</p>
        <p:graphicImage value="/images/ajax-loader.gif"/>  
    </p:blockUI>
</h:form>

Take a look at http://www.primefaces.org/showcase/ui/blockUI.jsf for more info.