title: Correct JSON  and Model with TreeStore and TreePanel
body: <p>I have a JSON String comes from the server side:</p>
  
  <pre><code>{"success":"true","total":"6","list":
    [{"id":"1","name":"folder1","parentid":"null","type":"0"},
     {"id":"2","name":"r1","parentid":"1","type":"1"},
     {"id":"3","name":"folder2","parentid":"1","type":"0"},
     {"id":"4","name":"r2","parentid":"3","type":"1"},
     {"id":"5","name":"r3","parentid":"null","type":"1"},
     {"id":"6","name":"folder3","parentid":"null","type":"0"}]}
  </code></pre>
  
  <p>How do I turn that into a tree?  Can anyone suggest me how to get the elements in the list (id, name, parentid, type)?</p>