Getting field values of a javascript object

Question

I've been using rhino to allow the customization of some applications. Here is an example of JavaScript function that is called from Java:

        function() {
            var phone = this.telephoneNumber;
            phone = phone.replace(/[^+0-9]/g,"");
            if (phone.indexOf("+") == 0) {
                phone = "00" + phone.substring(1);
            }
            if (phone.indexOf("0041") == 0) {
                phone = "0" + phone.substring(4);
            }
            if (phone.indexOf("0") == 0) {
                phone = "0" + phone;
            }
            return {
                Name: this.sn + " " + this.givenName,
                firstName: this.givenName || "",
                lastName: this.sn || "",
                phone: phone,
                service: "",
                info: ""
            };
        }

The java application can then get the values of the returned object for whatever it needs to do.

Now that rhino is part of the JVM, I would like to use the scripting API instead of the Rhino API, but I haven't found how to get the field values of a JavaScript object from Java code.

Answer 1

This loosely couples the scripting language, but with the caveats that the functions need to be named, and the returned object needs to be a Map (Rhino does this, but I'm not sure about JRuby).

    ScriptEngineManager factory = new ScriptEngineManager();
    ScriptEngine engine = factory.getEngineByName("JavaScript");
    engine.eval("function x() { return { foo: 10 } }");

    Object o = ((Invocable)engine).invokeFunction("x");
    if (o instanceof Map) {
    Map m = (Map<Object, Object>)o;
        System.out.println(m.get("foo"));
    }

or

    CompiledScript script = ((Compilable)engine).compile("(function() { return {bar:20} })()");
    System.err.println(((Map)script.eval()).get("bar"));

But you have to cheat and call your function by padding it with (...)().