JSViews - failed to load data after setTimeout

Question

I referred to the sample code stated in here and I have amended the following code

  data = {items: [
    {showItem:true, name:"Johnny Depp2"},
    {showItem:false, name:"Henry Best"}
  ]}

to

data = {},

helpers = {
    updateItem: function(ev) {
        $.observable(this).setProperty("showItem", !this.showItem);
    }
};

setTimeout(function () {
  data = {items: [
    {showItem:true, name:"Johnny Depp2"},
    {showItem:false, name:"Henry Best"}
  ]}
}, 1000);

but I found the initial data could not be loaded, could anyone teach me how to do this? I am simulating the Ajax page load, thanks very much.