helloworld.js

glu.defModel('helloworld.nav', {
  treestore: {
    mtype: 'treestore',
    proxy: {
      type: 'ajax',
      url: 'nav.json',
      reader: {
        type: 'json'
      }
    }
  },

  init: function() {
    this.treestore.load();
  }
});

glu.defView('helloworld.nav', {
  xtype: 'treepanel',
  region: 'west',
  store: '@{treestore}',
  rootVisible: false,
  title: 'My Navigation'
});

glu.defModel('helloworld.main', {
  navModel: {
    mtype: 'helloworld.nav'
  }
});

glu.defView('helloworld.main', {
  title:'TreeNav',

  items: [{
    xtype: '@{navModel}'
  }, {
    region: 'center',
    html: 'main content'
  }]
});