gistfile1.java

package org.vertx.java.platform.impl;

import javax.script.*;

import jdk.nashorn.api.scripting.ScriptUtils;

public class HandlerScopeTest {
  public static void main(String[] args) {
    new HandlerScopeTest().run();
  }

  private String script1 =

    "var myobj = {                         \n" +
    "  setCallback: function(cbk) {        \n" +
    "   _javaobject.setCallback(cbk)       \n" +
    "  }                                   \n" +
    "}                                     \n" +
    "// Try setting cbk - this works fine  \n" +
    "myobj.setCallback(function() {        \n" +
    "});                                   \n" +
    "_javaobject.setObject(myobj);";


  // But setting callback from different scope fails!
  private String script2 =
      "myobj.setCallback(function() {      \n" +
      "});                                  \n";


  private void run() {
    try {
      ScriptEngineManager factory = new ScriptEngineManager();
      ScriptEngine engine = factory.getEngineByName("nashorn");

      // Run script1 in it's own scope
      ScriptContext ctx = new SimpleScriptContext();
      Bindings bindings = engine.createBindings();
      bindings.put("_javaobject", this);
      ctx.setBindings(bindings, ScriptContext.ENGINE_SCOPE);
      engine.eval(script1, ctx);

      // And this one in another scope
      ctx = new SimpleScriptContext();
      bindings = engine.createBindings();
      bindings.put("myobj", myobj);
      ctx.setBindings(bindings, ScriptContext.ENGINE_SCOPE);
      engine.eval(script2, ctx);

    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  private Object myobj;

  public void setObject(Object obj) {
    myobj = ScriptUtils.wrap(obj);
  }

  public void setCallback(Runnable cbk) {
    System.out.println("Setting callback on Java object: " + cbk);
  }




}