Use already instanciated Java class in Jirb

luislavena · September 27, 2011, 3:23pm

Hi!

I’m trying to integrate the JRuby console JIRB, inside an existing
JFrame based application.

It works correctly and I can instanciate and use Java classes, from
“irb>” console.

Now I am trying use an application class that is already instanciated.

Is it possible to pass to Jirb a reference to that instance ?

All examples I manage do search for, always create a new instance inside
“jirb>”. I don’t want to do that.

Thanks,

Eduardo

edresende · September 27, 2011, 3:35pm

On Tue, Sep 27, 2011 at 8:23 AM, Eduardo R. [email protected]
wrote:

Is it possible to pass to Jirb a reference to that instance ?
It’s definitely possible, though the specifics depend upon which
embedding API you’re using.

Here’s an example I have using the JSR 223 embedding approach:

github.com

ajuckel/net.juckel.osgirubytest/blob/master/src/main/java/net/juckel/osgijrubytest/Application.java#L32


      
          public class Application implements IApplication {
          
          
//	@Override
          	public Object start(IApplicationContext context) throws Exception {
          		JRubyEngineFactory fact = new JRubyEngineFactory();
          //		fact.setClassLoader(this.getClass().getClassLoader());
          		JRubyEngine engine = (JRubyEngine)fact.getScriptEngine();
          		// engine.getContext().setWriter(new OutputStreamWriter(System.out));
          		//engine.getBindings(ScriptContext.ENGINE_SCOPE).put("foo", this.getClass().getClassLoader());
          		Bindings bindings = engine.getBindings(ScriptContext.ENGINE_SCOPE); 
          		bindings.put("foo", this.getClass().getClassLoader());
          		bindings.put("out", System.out);
          		try {
          			InputStream stream = this.getClass().getResourceAsStream("/src/main/ruby/simple.rb");
          			// URL jirb = b.getEntry("/META-INF/jruby.home/bin/jirb_swing");
          	//		engine.eval(new InputStreamReader(jirb.openStream()));
          			Object returnValue =  engine.eval(new InputStreamReader(stream), bindings);
          	//		System.out.printf("Value: %s; %s", returnValue.getClass().getName(), returnValue.toString());
          			return Integer.valueOf(0);
          		} catch ( Exception e ) {
          			e.printStackTrace();

Note that after putting this value in the scope with the name “foo”,
it’s available within Ruby code as a global variable, so must be
accessed as $foo.

edresende · September 27, 2011, 7:34pm

Hello!

On Tue, Sep 27, 2011 at 9:34 AM, Anthony J. [email protected]
wrote:

Is it possible to pass to Jirb a reference to that instance ?

It’s definitely possible, though the specifics depend upon which
embedding API you’re using.

Here’s an example I have using the JSR 223 embedding approach:

github.com

ajuckel/net.juckel.osgirubytest/blob/master/src/main/java/net/juckel/osgijrubytest/Application.java#L32


      
          public class Application implements IApplication {
          
          
//	@Override
          	public Object start(IApplicationContext context) throws Exception {
          		JRubyEngineFactory fact = new JRubyEngineFactory();
          //		fact.setClassLoader(this.getClass().getClassLoader());
          		JRubyEngine engine = (JRubyEngine)fact.getScriptEngine();
          		// engine.getContext().setWriter(new OutputStreamWriter(System.out));
          		//engine.getBindings(ScriptContext.ENGINE_SCOPE).put("foo", this.getClass().getClassLoader());
          		Bindings bindings = engine.getBindings(ScriptContext.ENGINE_SCOPE); 
          		bindings.put("foo", this.getClass().getClassLoader());
          		bindings.put("out", System.out);
          		try {
          			InputStream stream = this.getClass().getResourceAsStream("/src/main/ruby/simple.rb");
          			// URL jirb = b.getEntry("/META-INF/jruby.home/bin/jirb_swing");
          	//		engine.eval(new InputStreamReader(jirb.openStream()));
          			Object returnValue =  engine.eval(new InputStreamReader(stream), bindings);
          	//		System.out.printf("Value: %s; %s", returnValue.getClass().getName(), returnValue.toString());
          			return Integer.valueOf(0);
          		} catch ( Exception e ) {
          			e.printStackTrace();

Cool!

Note that after putting this value in the scope with the name “foo”,
it’s available within Ruby code as a global variable, so must be
accessed as $foo.

This is a default behavior. You can change to other one really natural
to Ruby.
See, RedBridge · jruby/jruby Wiki · GitHub

Eduardo:
You can choose to use ScriptingContainer. I guess you don’t use other
languages from the same Java code. In such a case, ScriptingContainer
would be easier to use.

-Yoko

edresende · October 4, 2011, 4:05pm

Hi!

Thanks for the replies but I still did not managed to make it work.
I didn’t explain exactly what I am trying to accomplish.

I found an example based on java class TextAreaReadline.
This shows a console inside a Java Swing JFrame.
From the example I only have two class instances available: Ruby and
RubyInstanceConfig. From the Javadoc, I could not interpret if some of
its method could help me.

Without using JSR 223 and BSF approaches, how do I manage to pass Java
objects to the TextAreaReadline “console” ?

I found “org.jruby.javasupport.JavaEmbedUtils.java” class also. Does it
help?

Thanks,

Edu

edresende · October 4, 2011, 6:15pm

Hi,

On Tue, Oct 4, 2011 at 10:22 AM, Eduardo R. [email protected]
wrote:

runtime.getGlobalVariables().set(GlobalVariable.variableName(“rbComponent”),
rbComponent);

You can do like above, but is not recommended.
Do you know JRuby has embedding API? If not,
RedBridge · jruby/jruby Wiki · GitHub will help you how to do
that.

Hope this helps,
-Yoko

edresende · October 4, 2011, 4:22pm

Hi!

Found what I was looking for.
I only needed to call these lines:

Component myComponent = …; // this is my object

IRubyObject rbComponent =
JavaEmbedUtils.javaToRuby(runtime, myComponent);

runtime.getGlobalVariables().set(GlobalVariable.variableName(“rbComponent”),
rbComponent);

Inside JRuby console, i could access that object:

irb(main):002:0> $rbComponent
#Java::PtEfacecSeAutComponentsEvtsuite::EvtSuiteComponent:0x10dba0d