GWT JSNI: invoking applet methods?

Question

I have a GWT application that includes an embedded applet.

I would like to use JNSI to let GWT buttons push data to that applet, but at the moment I can't even get it to connect. Looking for some help - can't seem to find anything addressing how to make things talk.

In my entrypoint class I define:

 native void doSomething() /*-{
  $doc.applet_id.doSomething();
 }-*/;

Which I hook via ClickHandler to a Button. Within the applet main class, there is a doSomething() method, and in the page I launch the applet via:

 <script>
  var attributes = {codebase:'http://localhost:8888/',
                    code:'Applet.class', archive:'applet_test.jar', id:'applet_id',
                    width:100, height:40} ; 
  var parameters = {fontSize:16, jnlp_href:'launcher.jnlp'} ; 
  var version = '1.6' ; 
  deployJava.runApplet(attributes, parameters, version);
 </script>

The stack trace is

 com.google.gwt.event.shared.UmbrellaException: One or more exceptions caught, see full set in UmbrellaException#getCauses
  at com.google.gwt.event.shared.SimpleEventBus.doFire(SimpleEventBus.java:214)
  at com.google.gwt.event.shared.SimpleEventBus.fireEvent(SimpleEventBus.java:103)
  at com.google.gwt.event.shared.HandlerManager.fireEvent(HandlerManager.java:96)
  at com.google.gwt.user.client.ui.Widget.fireEvent(Widget.java:107)
  at com.google.gwt.event.dom.client.DomEvent.fireNativeEvent(DomEvent.java:116)
  at com.google.gwt.user.client.ui.Widget.onBrowserEvent(Widget.java:155)
  at com.google.gwt.user.client.DOM.dispatchEventImpl(DOM.java:1308)
  at com.google.gwt.user.client.DOM.dispatchEvent(DOM.java:1264)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
  at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
  at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:157)
  at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:326)
  at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:207)
  at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:126)
  at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:561)
  at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:269)
  at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
  at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
  at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:214)
  at sun.reflect.GeneratedMethodAccessor56.invoke(Unknown Source)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
  at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
  at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:157)
  at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:281)
  at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:531)
  at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:352)
  at java.lang.Thread.run(Thread.java:680)
 Caused by: com.google.gwt.core.client.JavaScriptException: (TypeError): $doc.applet_id.doSomething is not a function

Answer 1

Apparently my jnlp file also needed

<param name="MAYSCRIPT" value="true"/>

in the <applet-desc> portion. Adding MAYSCRIPT:true to the attributes, however, did not seem to work.