title: ExtJS 4.2.0 RowExpander with load data dynamic
body: <p>I wanna use the ExtJs plugin "RowExpander", but, I would load the data when the event expandbody is fired.
  I've try this code, but I don't know how set the content of the rwoBody Expanded:</p>
  
  <pre><code>this.GridPrincipal.getView().addListener('expandbody', function (rowNode, record, expandRow, eOpts) {
  
  
          Ext.Ajax.request({
              url: 'getData/' + record.get('id'),
              method: 'POST',
              success: function (result, request) {
              // retrive the data
              var jsonData = Ext.util.JSON.decode(result.responseText);
              //code to change the text of the RowBody
                              //....
              },
              failure: function (result, request) {
              Ext.MessageBox.alert('Failed', result.responseText);
              return false;
              }
              });
  
  
  
      });
  </code></pre>
  
  <p>Thank you very much.</p>