GWT in Action, Second Edition

11.5. Handling objects from JavaScript

Our last example didn’t create anything while in the JSNI call, that is, no JavaScript objects, for example, but we did say the first parameter passed in was a JavaScript-Object, and now is the time to explore that further.

A JavaScriptObject is a Java object representing an object that’s been created in JavaScript. For example, the GWT Java Element object represents a DOM element created in JavaScript deep in the bowels of GWT when it creates a widget. We can’t create a JavaScriptObject object ourselves in Java code, that is, no new JavaScript-Object() calls; it can only be created automatically as the JavaScript object passes across the boundary from JavaScript to Java.

You can use JavaScriptObject ...