From: Zach Dennis <zdennis@...>
Date: 2005-08-02T07:04:53+09:00
Subject: Re: module / inheritance question

Joe Van Dyk wrote:
> class Parent
>   def foo
>     puts "Parent::foo called"
>   end
> end
> 
> module TheModule 
>   def self.boo
>     foo
>   end
> end
> 
> class Child < Parent
>   include TheModule
>   def initialize
>     super
>   end
> 
>   def boo
>     TheModule.boo
>   end
> end
> 
> Child.new.boo
> 
> # Two questions:
> # 1)  Why do I need Child.boo?  Shouldn't function TheModule.boo be mixed in
> #     to Child?

Because you defined boo as a module method on TheModule. Instance 
methods are mixed into classes:
   module TheModule
     def boo
     end
   end


> # 2)  Any way I can get TheModule.boo to call Parent.foo?

class Parent
   def foo
     "foo"
   end
end

module M
   def boo
     foo
   end
end

class Child < Parent
   include M
end

Child.new.boo => "foo"


> #
> #
> # What I'm really trying to do is something like this:
> 
> module MenuBarUtils
>   def create_menu title
>     # Creates a Gtk::Menu and then calls #append, a function that's in
>     # Gtk::MenuBar.
>   end
>   def add_menu_item menu, title, &action
>     # create menu item, attach it to menu, and bind &action to it
>   end
> end
> 
> class MyMenuBar < Gtk::MenuBar
>   include MenuBarUtils
>   def initialize
>     super
>     file_menu = create_menu "File"
>     add_menu_item(file_menu, "Quit") { exit }
>   end
> end

this appears to work fine... just change the definition of TheModule.boo 
to TheModule#boo

Zach