title: Insert a node at a specific location in Ext.tree.panel
body: <p>I'm trying to change this ext js treegrid sample:
  <a href="http://dev.sencha.com/deploy/ext-4.0.1/examples/tree/treegrid.html" rel="noreferrer">http://dev.sencha.com/deploy/ext-4.0.1/examples/tree/treegrid.html</a></p>
  
  <p>All I want is to add a node at a specific location.</p>
  
  <p>I tried this:</p>
  
  <pre><code> var treePanel = Ext.getCmp('treePanel');
   var selNode = treePanel.getSelectionModel().getSelection()[0];
   var appendedChild = selNode.appendChild({
                         task: 'Task1',
                         user: 'Name',
                         duration: '10',
                         leaf: true
                       });
  </code></pre>
  
  <p>It gives no errors, but the <strong>UI doesn't update.</strong> Same thing with <code>selNode.insertChild(0, ..</code> It runs with no errors, but the UI doesn't update.</p>
  
  <p>Somehow this <strong>works</strong>:</p>
  
  <pre><code>var node = treePanel.store.getRootNode();
  node.appendChild({
                      task: 'Task3',
                      user: 'Name',
                      duration: '10',
                      leaf: true
                  });
  </code></pre>
  
  <p>So how do I append/insert at a specific location <strong>based on user selection</strong>.</p>
  
  <p>Here is what my full code looks like: <a href="http://jsfiddle.net/4T68s/" rel="noreferrer">http://jsfiddle.net/4T68s/</a><br>
  I changed the store to static data because a crossdomain request to get the <code>json</code> data wouldn't work.</p>