Hi all,
I'm having some trouble with trying to dynamically load a module at runtime.
The following example demonstrates the problem I'm encountering.

dyninclude.rb
--------------------
class DynamicInclude
  def initialize(dynmod)
    DynamicInclude.load_module(dynmod)
  end

  def DynamicInclude.load_module(modname)
    load "#{modname}.rb"
    include Object.const_get(modname.to_s)
  end
end

Hello.rb
--------------------
module Hello
  def greeting
    puts "Hello"
  end
end

Goodbye.rb
--------------------
module Goodbye
  def greeting
    puts "Goodbye"
  end
end

Example
--------------------
d = DynamicInclude.new("Hello")
d.greeting() # prints Hello
e = DynamicInclude.new("Goodbye")
e.greeting() # prints Goodbye
d.greeting() # prints Goodbye

So, how can I dynamically include multiple module without the negative side
effect of previous class instances inheriting the new methods? I'm suspecting
that the fact that load_module is a class method is playing a role here, but
I can't make it work without making load_module a class method. Any help would
be appreciated.

Sincerely,
Travis Whitton <whitton@atlantic.net>

>>>>> "T" == Travis Whitton <whitton@atlantic.net> writes:


 Try this

T> class DynamicInclude
T>   def initialize(dynmod)
T>     DynamicInclude.load_module(dynmod)

       extend(Object.const_get(dynmod.to_s))

T>   end

T>   def DynamicInclude.load_module(modname)
T>     load "#{modname}.rb"
T>     include Object.const_get(modname.to_s)

  you don't need this include

T>   end
T> end

 Now if you are sure that these previous module don't exist you can write

svg% cat b.rb
#!/usr/bin/ruby

class DynamicInclude
   def initialize(dynmod)
      DynamicInclude.load_module(dynmod)
      extend(Object.instance_eval { remove_const(dynmod.to_s) })
   end

   def DynamicInclude.load_module(modname)
      load "#{modname}.rb"
   end
end

d = DynamicInclude.new("Hello")
d.greeting() # prints Hello
e = DynamicInclude.new("Goodbye")
e.greeting() # prints Goodbye
d.greeting() # prints Goodbye
svg% 

svg% b.rb
Hello
Goodbye
Hello
svg% 

 The load is made in Object, then the constant is removed to don't pollute
 Object 


Guy Decoux

Guy,
Thanks very much! That solved my problem perfectly. I love the Ruby community.

Travis

In article <200309151635.h8FGZgT05555@moulon.inra.fr>, ts wrote:
>>>>>> "T" == Travis Whitton <whitton@atlantic.net> writes:
> 
> 
>  Try this
> 
>T> class DynamicInclude
>T>   def initialize(dynmod)
>T>     DynamicInclude.load_module(dynmod)
> 
>        extend(Object.const_get(dynmod.to_s))
> 
>T>   end
> 
>T>   def DynamicInclude.load_module(modname)
>T>     load "#{modname}.rb"
>T>     include Object.const_get(modname.to_s)
> 
>   you don't need this include
> 
>T>   end
>T> end
> 
>  Now if you are sure that these previous module don't exist you can write
> 
> svg% cat b.rb
> #!/usr/bin/ruby
> 
> class DynamicInclude
>    def initialize(dynmod)
>       DynamicInclude.load_module(dynmod)
>       extend(Object.instance_eval { remove_const(dynmod.to_s) })
>    end
> 
>    def DynamicInclude.load_module(modname)
>       load "#{modname}.rb"
>    end
> end
> 
> d = DynamicInclude.new("Hello")
> d.greeting() # prints Hello
> e = DynamicInclude.new("Goodbye")
> e.greeting() # prints Goodbye
> d.greeting() # prints Goodbye
> svg% 
> 
> svg% b.rb
> Hello
> Goodbye
> Hello
> svg% 
> 
>  The load is made in Object, then the constant is removed to don't pollute
>  Object 
> 
> 
> Guy Decoux
>