Question

Parameter:
url -- In JSON format as specified in addData
asyncLoadCallback -- Callback function to be executed on completion of data loading

Loads data to the controller of Gio and overrides previous data asynchronously. The data source can be
specified through an URL. Data must be in JSON format as specified in addData.
The callback
function will be executed when the data finishes loading. Usage:

var url = "sampleData.json";

// Use addDataAsync() API to load the data from a URL asynchronously.
// The callback will be executed on completion of data loading.

controller.addDataAsync( url, asyncLoadCallback );

function asyncLoadCallback () {

        controller.init();

}