jsf 2 - JSF f:event preRenderView is triggered by f:ajax calls and partial renders, something else?

Question

So we have an f:event:

   <f:metadata>
    <f:event type="preRenderView" listener="#{dashboardBacking.loadProjectListFromDB}"/>
   </f:metadata>

Which is triggered as desired on initial page load (render).

However this preRenderView event is also triggered by an ajax partial page render, which re-renders an h:panelgroup with the id projectListing, as below.

<h:commandButton action="#{mrBean.addProject}" value="Create Project"
                                     title="Start a new project">
   <f:ajax render="projectListing" />
</h:commandButton>

I only want the dashboardBacking.loadProjectListFromDB to be called for the initial page render, but not when there is an ajax partial render. Is there a more appropriate event or method I could be using?

Answer 1

I had the same need not too long ago. I ended up using something suggested by BalusC.

There is a method in the FacesContext class that lets you know if you're dealing with a full blown request or a partial processing of some sort:

FacesContext.getCurrentInstance().isPostback()

This way you can still use the preRenderView technique and check if it's a postback in the listener. I found that particularly useful because I needed a session bean as the user had to navigate to another page and come back. If I used view scoped beans (like suggested above by Brian), I'd lose the info I had before navigating away.