callback in ComponentLibrary?

Hello people. I'm a beginner at Roku and I need help.
I am developing a ComponentLibrary. I'm already able to pass parameters via the interface and I can also use callFunc.
Comparing to the javascript, I would like to pass into the ComponentLibrary, a function that would be invoked at the end of an action inside the ComponentLibrary. Whoever is importing this ComponentLibrary, would hear this callback.
can you help me?