From: Timothy Bauscher <timothy@...>
Date: 2003-02-24T08:18:51+09:00
Subject: dynamic include

I'm developing a program which needs to dynamically load
and unload modules, adding the methods of each module to
a class. ``include'' is giving me trouble.

The following seems logical to me, but "include" isn't
known inside the method:

class Quinn
   def quinn_loadModule(modname)
      load "modules/#{modname}.rb"
      include #{modname}
   end
end

The following also doesn't work as I expected it to.
Although it executes without error, the methods in
the module are not extended into the class:

class Quinn < Module
   def quinn_loadModule(modname)
      load "modules/#{modname}.rb"
      include #{modname}
   end
end

The following works, but it feels dirty:

class Quinn
   def quinn_loadModule(modname)
      require "ftools"

      tmp = File::new("module.tmp", "w+")
      tmp.puts "load \"modules/#{modname}.rb\""
      tmp.puts "include #{modname}"
      tmp.close

      load "module.tmp"
      File::safe_unlink("module.tmp")
   end
end

I'm aware of extend_object(), but requiring modules to
add themselves to a particular object, IMO, takes away
the modularity from a module.

Any ideas are welcome.

-- 
timothy(at)linuxfromscratch.org

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