Richfaces custom components with actionlistener as input parameter

Question

With a custom component how can one make it take an MethodExpression as input parameter.

The component XML is set up with:

    <property elonly="true">
        <name>customListener</name>
        <classname>javax.el.MethodExpression</classname>
    </property>

And when I try to add an listener to the custom component with:

... customListener="#{bean.listener} ...

I always get null value in my RendererBase.

Am I'm missing some vital XML configuration ?