In Javascript this is bound to the current function so when you want to keep a reference to an "outer" object you see the pattern: var self = this;

as in:

var self = this;
return function(whatever) {
  return self.foo(whatever); // `this` here is for the inner function
}

• Is var self = this; a bad pattern?
  • Do what feels right
• What underlies this JavaScript idiom: var self = this?
  • Find to do, but could be dangerous because there is a window.self - see also: Window.self
• Getting Out of Binding Situations in JavaScript
  • Awesome tutorial on how .bind works