A completely different way to solve this is to use Aspect-Oriented Programming (AOP). Your problem is that you want to do something when foo is called, but before foo executes and only the first time foo executes.

Aspect would be the Perl way to do this, but I don't know how to remove advice with it, so I'll demonstrate using Dojo. This is a Javascript library.

function foo () { ... };
function call_only_once () {
    dojo.event.disconnect( 'before', foo, call_only_once );
    // Do stuff here
};

dojo.event.connect( 'before', foo, call_only_once );

foo();
[download]