UWA provides an advanced programming experience through its JavaScript framework.

The JS framework provides the developer with many events and methods, encapsulated in JavaScript objects, the most important one being the widget object, an instance of the UWA Widget class.

The widget object replaces the document DOM object. Most of its events and methods are alternatives to their JavaScript/DOM counterparts, which in the restricted environment are unavailable or limited.

Since the Widget class is automatically instantiated by the Netvibes environment (or the emulation profile, in the case of standalone widgets), the widget object and its events and methods are directly accessible throughout your widget's JavaScript code.

The widget object handles the following events:

These methods are triggered by specific widget methods, but are also available for your own code.

Those events are triggered internally. If needed, they can be triggered manually. For instance, in order to have the widget adapt its size to its content, this line should be added at the end of the DOM-updating code:

widget.callback('onUpdateTitle');

The widget object provides the following methods.

createElement 's options parameter can greatly shortern your element-creating code:

1. if options is not defined, it works just like document.createElement(tagName) ;
2. if options is defined, its works like JS frameworks DOM builders: new Element(tagName, options). options takes the form of a JSON-like object

Examples:

var div = widget.createElement('div');
 
var input = widget.createElement( 'input', 
  { 'type': 'submit', 'value': 'Update' } );

The widget object provides the following properties:

The following methods are available to HTML elements that are UWA-extended, within the widget body tag. Elements are automatically UWA-extended when they are created using widget.createelement(). The body tag is extended by default.

var p = UWA.extendElement( 
  widget.body.getElementsByClassName("myElement")[0] 
);
p.setStyle("backgroundColor", "red");

In the following tables, el is any applicable element (including widget.body).

Ajax is a central part of UWA widget development. UWA developers should rely on the UWA.Data object for data requests.

All of UWA.Data's methods pass the Ajax request's responseText/responseXML value as a first argument of the given callback method.