title: How to implement sorting in EXTJS Grid
body: <p>I am facing a problem in extjs grid . I have two grid column one is name and another is displayName but I want to sorting by name in both column means I displayName as well as name. When user apply sort in both column parameters pass by grid is sort= name in both case.</p>
  
  <pre><code>[
          {
              header: 'Name',
              dataIndex: 'name',
              shortable: true
          },
          {
              header: 'DisplyName',
              dataIndex: 'displayName',
              shortable: true
          }
      ]
  </code></pre>