Nashorn pass script engine arguments

[Puckfist]

If one passes the -scripting argument to the NashornScriptEngineFactory they get the various functions described here: https://docs.oracle.com/javase/8/docs/technotes/guides/scripting/nashorn/shell.html

Which seems like it would be most useful for a dynamic interaction with the shell

I think we'd have to do this by changing the ScriptUtils.newEngine to call the NashornScriptEngineFactory directy if we wished to do this, or offer it as an option, similar to (but probably not exactly) this (call getScriptEngine I think, not getEngine): https://stackoverflow.com/questions/26873201/enable-scripting-mode-for-nashorn-in-java

[jazdw]

Are we using Nashorn for shell scripting anywhere? I don't see the usefulness of these options for a meta data point script for example.

[Puckfist]

No, we're not. The thought was more along the lines of someone could write a really powerful scripting data source. They'd have tools for synchronous HTTP and synchronous shell actions!

Perhaps just providing command line arguments to nashorn, as there are other arguments a user may like.

[jazdw]

If we do want to do this it seems we could re-implement ScriptUtils.newEngine() as follows. It also enables ES6 features (only let and const in Java 8).

    public static ScriptEngine newEngine() {
        ScriptEngineManager manager = new ScriptEngineManager();
        List<ScriptEngineFactory> factories = manager.getEngineFactories();
        for (ScriptEngineFactory factory : factories) {
            if (factory instanceof jdk.nashorn.api.scripting.NashornScriptEngineFactory) {
                return ((jdk.nashorn.api.scripting.NashornScriptEngineFactory) factory).getScriptEngine("-scripting", "--language=es6");
            }
        }
        return manager.getEngineByName("js");
    }

Alternatively use command line options -Dnashorn.option.scripting=false and -Dnashorn.option.language=es6