From: "Mark J. Reed" <markjreed@...>
Date: 2003-07-30T11:09:47+09:00
Subject: Re: Passing a method block to a parent class

On Sun, Jul 27, 2003 at 07:58:50AM -0700, Eric Anderson wrote:
> If I have
> 
> **** CODE ****
> 
> class A
> def method1( argument )
>     yield( argument )
> end
> end
> 
> class B < A
> def method1( argument )
>     puts argument
>     super.method1( argument )
> end
> end
> 
> obj = B.new
> obj.method1( 'foo' ) { |arg| puts arg + 'bar' }
> 
> **** CODE ****
> 
> How do I change this to allow class A to get the block. Bascially I
To pass blocks around you have to use proc arguments.

If you declare a method thus:

	def method2 (argument, &block)
	end

Then any block associated with a call to the method will be turned into
a Proc object and assigned to the &-marked parameter (which must be last
in the list).  Like *, this works both ways; if you pass a Proc as the
last parameter of a method call and put a & in front of it, the called
method sees it as a block.  

So this should do what you want:

    class B < A
	def method1( argument, &block )
	    puts argument
	    super.method1( argument, &block )
	end
    end

-Mark