On 10/12/13 16:04, Attila Szegedi wrote:
Indeed. These objects aren't native JavaScript objects; they don't
even implement JSObject or extend ScriptObject - they're host objects
(just as any POJO technically is). Nashorn's execution model is such
that it can handle objects of multiple kinds - native JS objects,
POJOs, statics, etc. without ever wrapping them internally thanks to a
variety of dynamic linkers it employs, so these objects don't have a
wrapped representation. Just as you couldn't pass the result of "new
java.util.ArrayList()" to a method expecting JSObject, neither can you
pass the objects representing statics, as they don't have a wrapped
JSObject representation. This is in general true for anything coming
from the script host environment - in this case, the JVM.
If you want to opportunistically wrap in a mirror anything that can be
wrapped in a mirror (and get a graceful NOP otherwise), declare your
Java API to accept Object, and invoke ScriptUtils.wrap() explicitly -
that'll wrap ScriptObject instances into mirrors, and return any other
object unchanged.
Thanks, I adapted the code to use ScriptUtils.wrap() and encountered a
strange situation where JSON.stringify returns undefined for a valid JS
object. Maybe another scope problem?
Here is a reproducer: https://gist.github.com/purplefox/7893408
Basically I have two scripts:
In one I have a function which takes an argument and displays the result
of JSON.stringify on it. The first script exports the function by
calling a setFunction() method on a Java object which wraps the object
using ScriptUtils as you suggested.
I then invoke another script in a different context and pass in the
wrapped foo function and the script calls it, when it does the output is
as follows:
Before call, conf stringified is {"f":"bar"}
config.f is bar
in foo, conf stringified is undefined
Weird!
