ScriptObjectMirror - reformatted for plain text

A. Sundararajan sundararajan.athijegannathan at
Mon Jul 14 10:56:44 UTC 2014

Hi Rod,

Nashorn allows only script objects (i.e., objects created by a JS 
constructor or JS object literal expression) as scope expression for 
"with" statement. Arbitrary objects like "context" (which is an instance 
of javax.script.ScriptContext) can not be used as 'scope' expression for 

In jdk9, support has been added to support script objects mirror other 
script engines or other globals (which are instances of ScriptObjectMirror).

What is ScriptObjectMirror?

it is java API for an underlying JS object (which is an instance of 

For eg. you can a ScriptObjectMirror like this:

     ScriptObjectMirror sobj = (ScriptObjectMirror) engine.eval("({ foo: 
233 })");

More info here:

Hope this helps,

On Friday 11 July 2014 12:49 PM, Rod Nim wrote:
> Dear Nashorn devs;
> I'm wanting to invoke a JS function that looks like this:
> function myFunc(context) {
>     with(context) {
>        return a + b;
>     }
> }
> Where a and b are values my Java "context" object supplies.
> I've tried passing in "context" from Java (via Invocable) as a Map; and am getting:
>     javax.script.ScriptException: TypeError: Cannot apply "with" to non script object in <eval>
> Fair enough. So I tried my own instance of JSObject but Nasorn isn't happy with that either, same exception.
> So myArg needs to be an instance of ScriptObjectMirror. But ScriptObjectMirror is final!
> Any way to get me out of his corner?
> Thank you in advance for your help. I know you're a very busy team and answering "user" questions like this is not a core priority, in fact I almost feel embarrassed to ask.
> Thanks again.
> Rod  		 	   		

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