From: Joel VanderWerf <vjoel@...>
Date: 2004-08-17T13:31:50+09:00
Subject: Re: Embedding Ruby as plugin

Tobias Grimm wrote:
> Hi!
> 
> I have an application written in C++, that provides a plugin interface. 
> What I would like to do now, is to implement a plugin, that allows to 
> execute a ruby script, like this:
> 
> 1) Application loads plugin.so
> 2) Application invokes plugin
> 3) Plugin creates object "interface" of class Interface
> 4) Plugin loads rubyscript.rb
> 5) rubyscript.rb uses interface object created in 3) to send messages to 
> the plugin
> 
> I used SWIG to create a wrapper for the Interface class that the ruby 
> script should use. If I simply wanted to create an ruby extension, the 
> wrapper should just be compiled to a lib, that ruby can load with a 
> require statement. But now the wrapper is part of the plugin, which 
> itself is loaded by the application. How do I get the ruby script know 
> about the Interface class and the interface object to use?

Not sure I understand. Where is the ruby interpreter in this picture? 
Your C++ app embeds it? Or plugin.so embeds it?

What if you just set a global variable, $interface, before loading 
rubyscript.rb, which references this global?

Is the problem then that you don't want to use a global, for the usual 
good reasons?