title: dom references and global variables localization. does it make sense?
body: <p>Does it make more efficient to make a local( and private ) variables / DOM references if you use them in backbone view?</p>
  
  <pre><code>var app = {};
  
  (function( window, document ) {
    var variable = 'some data';
    var dom_reference = document.getElementById('some-id');
  
    app.view = Backbone.View.extend({
      // some action
    });
  })( window, document );
  </code></pre>