title: es6 classes and "this" with event handlers
body: <p>playing around with some es6 and ran into an issue i'm not sure how to solve. consider the following</p>
  
  <pre><code>class Foo {
   constructor ( ) {
     window.addEventListener('scroll', this.watch);
   }
  
   watch ( ) {
     console.log(this);
   }
  }
  </code></pre>
  
  <p>Inside of <code>watch</code>, <code>this</code> is the <code>window</code> object, as expected. But how do i refer to <code>Foo</code>? Currently I get around this with bind <code>this.watch.bind(this)</code> but i'd love to know if there is a more "proper" ES6 way to get this going.</p>