title: ExtJS: directfn and TreeStore - not loading
body: <p>What's the right way to use a TreeStore with directFn?</p>
  
  <p>Here's how I'm doing it: </p>
  
  <pre><code>var categoryStore = Ext.create('Ext.data.TreeStore', {
      //storeId:'categoryStore',
      autoLoad:true,
      root: {
          text: 'Menu',
          id: 'categoryId',
          expanded: true
      },
      proxy: {
          type: 'direct',
          directFn: categoryController.getMenuItems,
          reader: {
              id: 'categoryId'
          }
      },
      fields: ['categoryId', 'text', 'children', 'leaf', 'cls'],
      sorters: [{
          property: 'leaf',
          direction: 'ASC'
      }, {
          property: 'text',
          direction: 'ASC'
      }]
  });
  </code></pre>
  
  <p>But I get no love.  Here's sample of my data:</p>
  
  <p>[{"method":"getMenuItems","result":{"data":[{"children":[{"leaf":true,"checked":false,"categoryId":1001,"text":"XXXXX"}],"success":true},"action":"categoryController","tid":1,"type":"rpc"}]</p>
  
  <p>Frustratingly, it works if I put what's inside the data node and do a straightforward AJAX call.</p>