Subj : Re: creating JS objects in Java...?
To   : netscape.public.mozilla.jseng
From : user
Date : Thu Feb 17 2005 07:11 pm

thanks!
everything works!
man, i love this stuff. Rhino is *really* cool.

-denny-


Igor Bukanov wrote:

> user@domain.invalid wrote:
> 
>> getting there.
>> i think i compiled the class, now I have to do something with the 
>> bytes I just got back.  Do i need to define my own ClassLoader subclass?
> 
> 
> No, you can piggyback on the implementation that Rhino uses internally 
> and add something like the following to your code fragment:
> 
> ClassLoader parentLoader = ThisClass.class.getClassLoader();
> GeneratedClassLoader loader = mJsContext.createClassLoader(parentLoader);
> Class mainClass = null;
> for (int i = 0; i != objs.length; i += 2) {
>     Class cl = loader.defineClass((String)objs[i], (byte[])objs[i + 1]);
>     if (mainClass == null) mainClass = cl;
> }
> 
> The above uses the fact that it is the first class in objs that 
> extends/implements superclass/interfaces. It is also important to make 
> sure that parentLoader in the above code can be used to access both 
> Rhino classes and superclass/interfaces. In your case it would happen 
> automatically, but in general this is a thing to watch.
> 
> Then you can instantiate MainClass like in:
> 
> Module module = (Module)mainClass.newInstance();
> 
> Regards, Igor
> 
> 
>>
>> here's what i've got so far.  How's it look?
>>
>>
>> CompilerEnvirons ce = new CompilerEnvirons();
>> ce.initFromContext(mJsContext);
>> ClassCompiler cc = new ClassCompiler(ce);
>> cc.setMainMethodClass("MyCoolNewClass");
>> cc.setTargetExtends(Module.class);
>>
>> Class[] interfaces = {NamedObject.class};
>> cc.setTargetImplements(interfaces);
>>
>> String js = "function 
>> Start(){Packages.java.lang.System.err.println(this);} function 
>> GetName(){return this.toString();} function GetNamedChild(){return 
>> null;}";
>> Object[] objs = cc.compileToClassFiles(js, "script", 1, 
>> "MyCoolNewClass");
>>
>>
>> -denny-
>>
>>
>> user@domain.invalid wrote:
>>
>>> that's exactly perfect!
>>> Thank you!
>>>
>>> I don't really need the class files as actual files, but maybe it's 
>>> an interesting optimization to store them away and use the later...
>>>
>>> I've been looking at the javadocs and I can see roughly what's going 
>>> on.  Are there any examples anywhere where someone is doing this?  I 
>>> did a google search and didn't come up with much.
>>>
>>> thanks again - it's perfect.  now if I can just figure out how it 
>>> works...
>>>
>>> =)
>>> -denny-
>>>
>>>
>>>
>>>
>>> Igor Bukanov wrote:
>>>
>>>> user@domain.invalid wrote:
>>>>
>>>>> So, if I use the JavaAdapter to make c new javascript class that 
>>>>> inherits from another class an implements a few interfaces, if I 
>>>>> use the Rhino API to get a hold of that object in Java, can I use 
>>>>> it right then and there as an object of those interface types?  Or 
>>>>> do I have to use it as such only in the JS context?
>>>>>
>>>>> Here's what I want to do:  I have an engine that takes Module 
>>>>> objects. Many of these Module objects have been overwritten in Java 
>>>>> - EmailModule, etc.  I would like to be able to have the user 
>>>>> author his own Module using JavaScript, using, presumably, the 
>>>>> JavaAdapter.
>>>>>
>>>>> This authoring is done in a little gui.  Say that I have an 
>>>>> interface Foo which has an method Bar() that I want to overwrite.  
>>>>> So, in this gui he writes "function Bar(){print("HelloWorld");}".  
>>>>> Now, -in Java- how do I make this Module object with this code 
>>>>> overloading the superclass method Bar() such that I then have a 
>>>>> Java Module object that I can pass around my Java API?
>>>>>
>>>>> Basically, I want a Java function (not a JS function) like this:
>>>>>
>>>>> public Module BuildSubclass(String[] superclasses, String 
>>>>> iBarJSCode, String iSomeOtherMethodJSCode,...)
>>>>> {
>>>>>     Module m = new JavaAdapter(superclasses, iBArJSCode, 
>>>>> iSomeOtherMethodJSCode);
>>>>>
>>>>> return m;
>>>>> }
>>>>>
>>>>> Now I have a Module object that extends or implements an arbitrary 
>>>>> number of classes or interfaces and who has various overloaded 
>>>>> methods.
>>>>>
>>>>>
>>>>> How do I do this? I would be incredibly grateful for some help.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Use class compiler,
>>>> http://www.mozilla.org/rhino/apidocs/org/mozilla/javascript/optimizer/ClassCompiler.html 
>>>>
>>>> to compile you class to bytecode sublassing the desired class, load 
>>>> the generated bytecode into a class loader and instantiate the 
>>>> resulting class.
>>>>
>>>> Regards, Igor
>>>
>>>
>>>
>>>
>>

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