[Qt-interest] returning a QObject to javascript in WebKit

[Paul Dixon]

> I've  added an object to a QWebFrame with addToJavaScriptWindowObject,
> and successfully called a slot on that object from javascript.
>
> I'm having trouble getting that slot to return a new object.
> (snip!)


One rather ugly hack I'm now considering is to use
addToJavaScriptWindowObject to drop the object I want to return into
the window object with a random name, then have my slot return the
name of the object instance instead:

QString MyApp::helloWorld()
{
     //general a unique name for the js variable
     QString name=getRandomVariableName();

     //here's the object we want to expose to js
     MyObject* pReturn=new MyObject();

     //we make attach our object to the js window object
     getWebFrame()->addToJavaScriptWindowObject(name, pReturn,
         QScriptEngine::ScriptOwnership);

     //tell js the name we used
     return name;
}

The JS can be written to check if the return value is a string, and if
it is, grab the object from the window.:

var foo=myapp.helloWorld();
if (typeof foo == "string")
{
    foo=window[foo];
}

A little ugly, but will get me by until a better method comes along. I
see in the roadmap that future Qt versions are going unify the
scripting support so that it's all based on the JavaScriptCore in
WebKit, so hopefully this will improve then!