title: Update item views from Backbone collection add
body: <p>I have a <code>ListView</code> and <code>ItemView</code> for a list. <code>ListCollection</code> is used as the <strong>collection</strong> for <code>ListView</code>. Now if I get additional new collection (e.g. more items in the list) and <code>add()</code> into <code>ListCollection</code>, how should I go about <strong>rendering the list</strong> in general after <code>add</code> event? </p>
  
  <ol>
  <li><p>Should I do <code>collection.add(newCollection)</code>? And then loop through <code>newCollection</code> to add model by model while heave <code>ItemView</code> to bind into model's <code>add</code> event to render?</p></li>
  <li><p>Or should I loop through each model in <code>newCollection</code> to create new model, then add into <code>ListCollection</code>? Each loop with call <code>ItemView.render()</code></p></li>
  </ol>
  
  <p>What I don't want to do is to re-render the whole ListView which is too inefficient.</p>
  
  <p>Let me know if there is a good option between those two or a third one.</p>