javascript - How to get [[boundthis]] from function

Question

I need your help.
I have 2 functions:

addMoveListeners: function(e) {
  e = e || window.event;
  // Binging context to function move
  moveListener = MYAPP.move.bind(e.target.parentElement);
  //
  if (e.target.classList.contains('move')){
    document.addEventListener('mousemove', moveListener, false);
    document.addEventListener('mouseup', MYAPP.removeListener, false);
  }
  resizeListener = MYAPP.resize.bind(e.target.parentElement);
  if (e.target.classList.contains('resize')){
    document.addEventListener('mousemove', resizeListener, false);
    document.addEventListener('mouseup', MYAPP.removeListener, false);
  }
  return false;
},

and this:

removeListener: function(e){
  e = e || window.event;
  //Here I want get element from function
  console.dir(resizeListener);
  // Function stores it in [[BoundThis]]
  document.removeEventListener('mousemove', resizeListener, false);
  document.removeEventListener('mouseup', MYAPP.removeListener, false);
  document.removeEventListener('mousemove', moveListener, false);
  document.removeEventListener('mouseup', MYAPP.moveListener, false);
},

How can I get property [[BoundThis]] from function resizeListener without execution.

Answer 1

You cannot. [[BoundThis]] is an internal property of bound function objects. It is not programmatically accessible.

You might be able to view it with inspection of the object via console, but to use it in your program logic you will need to write your own version of bind that exposes this value as a property.