Why PageController method invoked multiple times per request

Question

I have a page with a customized PageController to override the "prepareModel(LifecycleContext)" method to create bindings dynamically for the page.
I expected the overridden method only invoked once per loading/refresh of the page.
From debugging, I found the overridden method actually invoked 3 times before the page was loaded.
When I put some logic so that bindings only created the 1st time the overridden method invoked, then the page failed to show the data properly as if the binding was missing.
With some debugging, I noticed the PageController invoked multiple times when I added the af:table to the page.
Any idea why prepareModel() got invoked multiple time per loading of a page with af:table ?
How do I determine when to create bindings within prepareModel() so that bindings only created once and the page can use the binding to show the data properly?

Answer 1

<executables>
<invokeAction id="onpageLoadClearTable" Binds="clearViewObject"
RefreshCondition="#{adfFacesContext.postback == false}"/> --------added this into your pagedef.
</executables>
<bindings>
<methodAction IterBinding="XXXXXXXXViewIterator" id="clearViewObject"
MethodName="clearViewObject" RequiresUpdateModel="true"
Action="999" IsViewObjectMethod="true"
</bindings>