porting event listeners

How do you port an event listener to a construct 2 conditional?

I'm trying to port MIDI.js but don't know how to integrate the MIDI.Player.addListener(function(data) {} ) conditional.

Does this make sense? If anybody requires more information to help answer my question, please let me know

p.s. yes, I am aware that there is already a MIDI.js port but MIDI is integral to my project and I require a high level of control over how this plugin works

Here's a recent example of making a callback:

Basically you add the function object ad you can then use:

c2_callFunction() in javascript to call a c2 function.

Here is another midi plugin.

I also have one midi plugin.