From: Avi Bryant <avi@...4.com>
Date: 2001-11-06T06:16:40+09:00
Subject: [ruby-talk:24427] Re: Detect future method calls in method_missing?


What you need is sometimes called a "trampoline" - an object that
simply "bounces" any messages it receives:

class Trampoline
	def initialize(&b)
		@callback = b
	end

	def method_missing(meth, *args)
		@callback.call(meth, *args)
	end
end

Then you should be able to do:

class MyClassWrapper
	def initialize
		@mc = MyClass.new
	end

	def method_missing(meth, *args)
		Trampoline.new  do |next_meth, *next_args|
			@mc.content.send(next_meth, *next_args)
		end
	end
end

Will that work for you?

On Tue, 6 Nov 2001, Morris, Chris wrote:

> Given this (contrived example for a real wrapper I'm writing):
>
>   class MyClass
>     attr_reader :content, :contentLength
>     def initialize
>       @content = 'test'
>       @contentLength = @content.length
>     end
>   end
>
>   class MyClassWrapper
>     def initialize
>       @mc = MyClass.new
>     end
>
>     def method_missing(methID, *args)
>       methodName = methID.id2name
>       @mc.content.send(methodName.intern, *args)
>     end
>   end
>
> Used this way:
>
>   w = MyClassWrapper.new
>   puts w.reverse
>   puts w.content.length
>
> Yields:
>
>   tset
>   ./default.method.in.wrapper.rb:16:in `send': undefined method `content'
> for "test":String (NameError)
>           from ./default.method.in.wrapper.rb:16:in `method_missing'
>           from -:3
>
> I understand why it does this. My question is this: is there a way, when
> w.content.length is called, from within method_missing("content") to know
> that ".length" will be coming next? (and in that case simply return
> @mc.content). My guess is no, there's no way for method_missing to know what
> future calls are coming down the pipe.
>
> Chris
>