Custom Components and passing arguments

Question

This afternoon i got a great answer regarding the use of custom MXML components and calling a function back in the main application file. I can accomplish this now by using parentDocument BUT I need to pass the name of a function(for filtering) as a parameter of the function call in the custom component. Below are the two code fragments.
Custom Component Code
<mx:LinkButton label="10% off or more" click="parentDocument.filterFunction(showTenPercent)" />
Main App Code
public function filterFunction(functionName:Function):void {
merchantDG.visible=true;
merchantData.filterFunction=functionName;
merchantData.refresh();
            public function showTenPercent(item:Object):Boolean {
                    return (item.merchantOfferCategory=="10%");
The filterFunction in the main App is called by multiple components so I believe I need to keep in centralized in the main app. There is probably another way to do this but I am building my Flex skills slowly and need to understand how to do this. As the code is now, I get an error about functions and strings.

Answer 1

I believe instead of calling the function from inside the custom component you need to do this from inside your main application whenever you're initiating the custom component.
for ex.
<custom:LinkBtnCustom label="10% off or more"  click="filterFunction(showTenPercent)"/>
this way you don't need the parentDocument prefix.