How do I bind a function to a component programatically in Actionscript?

Question

I am trying to provide my own labelFunction for a CategoryAxis programatically but am completely stumped. The regular way is to do it in your MXML file, but I want to do it in my Actionscript file.

The regular way of doing it is:

<mx:Script>
    <![CDATA[
       private function categoryAxis_labelFunc(item:Object, 
                prevValue:Object, 
                axis:CategoryAxis, 
                categoryItem:Object):String {
                return "Some String";
            }
      ]]>
</mx:Script>

<mx:CategoryAxis labelFunction="categoryAxis_labelFunc" />

But I want to achieve the same thing in my subclass of CategoryAxis, something like:

public class FauxDateAxis extends CategoryAxis {

    public function FauxDateAxis() {
        super();
        labelFunction = categoryAxis_labelFunc // Doesn't work of course.
    }

        private function categoryAxis_labelFunc(item:Object, 
                prevValue:Object, 
                axis:CategoryAxis, 
                categoryItem:Object):String {
            return "Another String";
    }   

}

Answer 1

Well, I'm baffled by your problem, because it works absolutely fine for me.

I took the example application for CategoryAxis from the Adobe Flex site: http://livedocs.adobe.com/flex/3/langref/index.html?mx/charts/CategoryAxis.html&mx/charts/class-list.html, added your code verbatim (well except for adding package and import statments), and it worked just like you want it to.

In the example, I modified the line

<mx:CategoryAxis id="haxis" categoryField="Date" title="Date"/>

to read

<local:FauxDateAxis id="haxis" categoryField="Date" title="Date"/>

and it displayed "Another String" at the base of each column.

I'm using Flex 3, if that matters.

Good Luck, Randy Stegbauer