Passing A Bound Object Method In Javascript

For a Firefox extension, I'm trying to do the following: Setup an object with two methods and a field/property/attribute One of the methods has to be able to call the other method

Solution 1:

Use the ES5 bind function:

varObj = {
  field: null,
  a: function() { }
  b: function() {
    this.a = 'x';
    this.a();   //Note: not sure what you're trying to do, but calling a string like a function won't work.
  }
}

window.addEventListener('mouseup', Obj.b.bind(Obj), false);

Solution 2:

bind is definitely a good approach. However, notice that addEventListener method can accept object that implements the EventListener interface, instead of a function:

varObj = {
  field: null,
  a: function() { },
  b: function() {
    this.field = 'x'; // if you overrides `a` you can't call itthis.a();
  },

  handleEvent: function(event) {
    switch(event.type) {
      case"mouseup":
         this.b();
         break;
    }
  }
}

window.addEventListener('mouseup', Obj, false);

This can be useful if you have multiple events related to Obj, and/or if you have multiple instances of the same object (not your case).