Problem with interoperability with JavaFX WebEngine

[A. Sundararajan]

Browser's DOM objects (like WebEngine's) implement 
netscape.javascript.JSObject interface. Such objects are treated 
specially by nashorn's linker.

http://hg.openjdk.java.net/jdk9/dev/nashorn/file/ca150ddd536e/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/linker/BrowserJSObjectLinker.java

is the dynalink linker that handles such objects. JSObject.getMember, 
putMember, call are used to provide property, call access seamlessly.

Please check out this example:

http://hg.openjdk.java.net/jdk9/dev/nashorn/file/ca150ddd536e/samples/browser_dom.js

So, what you're seeing is a bug in the way that linker works.  Let me 
check out and file a bug.

Thanks,
-Sundar


On Friday 27 March 2015 04:41 PM, David P. Caldwell wrote:
> So it's very cool, and unexpected, that JavaScript objects obtained
> from a JavaFX WebEngine show up as something like ordinary Nashorn
> objects in Nashorn scripts. That's an unexpected bonus (I was planning
> on using .setMember() and all that stuff from
> netscape.javascript.JSObject).
>
> The objects behave a bit strangely, though. So I've got a couple of
> bug reports, I guess.
>
> Here's a script that demonstrates the ones I've found so far:
>
> var WebEngine = Java.type("javafx.scene.web.WebEngine");
> var engine = new WebEngine();
>
> var window = engine.executeScript("window");
>
> print("foo = " + window.foo);
> print("typeof(window.foo) = " + typeof(window.foo));
> if (window.foo) {
>      print("window.foo is truthy");
> }
>
> Output:
> $ /usr/lib/jvm/jdk1.8.0_40/bin/jjs -fx nashorn.js
> foo = undefined
> typeof(window.foo) = string
> window.foo is truthy
>
> I actually am using a much more complicated embedding that is done
> from Java, so I can tell you the problem is not in the implementation
> of the -fx flag.
>
> Other than that, I can't see much; I haven't delved into the Nashorn
> code, let alone whatever magic enables this.
>
> -- David.