[flexcoders] invalidateList or itemUpdated?

[david.marr]

Hi,
I have an item renderer which checks an application scoped variable to
determine whether to show a display object. When that variable
changes, I need to make sure all the item renderers for the listbase
object (datagrid) i am using are refreshed. What is the best way to do
this?

the pseudocode for my item renderer would be something like:

if (Application.application.foo) {
  showButton = true;
} else { 
  showButton = false;
}

then in the Application, I need to somehow update the renderers:

foo.val = true;
<what do i do here to get the item renderers to update?>

thanks!
dave