title: dust.js reference object attributes using $idx
body: <p>I'm new to dust.js. Is there a way to reference object attributes using $idx. For ex:</p>
  
  <pre><code>{
    "table": [
      {
           "row":
           {
                 "ID": "1",
                 "Domain":"Domain 1"
           }
      },
      {
           "row":
           {
                "ID": "2",
                "Domain":"Domain 2"
           }
      }]
  }
  </code></pre>
  
  <p>How do I reference the ID attribute using $idx ? I might rename the columns ("ID","Domain") later-on and don't want the dustjs code to break.</p>
  
  <p>Thanks</p>