From: Joe Van Dyk <joevandyk@...>
Date: 2005-08-02T08:11:08+09:00
Subject: Re: module / inheritance question

On 8/1/05, Zach Dennis <zdennis@mktec.com> wrote:
> 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


Ah, thanks.