tree panel not load json file

[fpessoa]

Anyone know, how do I load the grid panel in preview mode?
loaded the json record date tree store = OK.
Fields created = OK
component of the config tree panel, property store = OK;

data are shown in the designer but not in preview mode.

In debug firefox, it is not loading the json file. There's no line like:
GET http://localhost:8080/extjs/examples/tree/check-nodes.json?_dc=132702417177 .....

[aconran]

Turn on autoLoad: true on the store.

[fpessoa]

man,
Only works when I add this line: "root:{}" into my file js. (SetoresJasonTreeStore.js).
perhaps,when I export again the project,this line is overwritten.
I can do something about it?



constructor: function(cfg) {
var me = this;
cfg = cfg || {};
me.callParent([Ext.apply({
autoLoad: true,
storeId: 'SetoresJsonTreeStore',
root:{},
proxy: {
type: 'ajax',
url: 'data/json/treenodes1.json',
reader: {
type: 'json'
},