From: Robert Klemme <shortcutter@...>
Date: 2009-05-20T05:45:03+09:00
Subject: Re: Super super ?

On 19.05.2009 21:29, Marc-antoine Kruzik wrote:
> Hello, I'm looking for informations about "super".
> 
> I have 3 classes : grandfather, father, and son.
> And they all have a method named "say_hello".
> 
> 
> 
> [code]
> class Grand_father
>   def say_hello
>     puts "Grand Father : Hello"
>   end
> end
> 
> class Father < Grand_father
>   def say_hello
>     super
>     puts "Father : Hello"
>   end
> end
> 
> class Son < Father
>   def say_hello
>     super
>     puts "Son : Hello"
>   end
> end
> [/code]
> 
> s = Son.new
> s.say_hello
> Grand Father : Hello
> Father : Hello
> Son : Hello
> 
> But now, I would that Son didn't call Father, but directly Grand_father.
> 
> s.say_hello
> Grand Father : Hello
> Son : Hello
> 
> How could I do that ?

You can do

class Son < Father
   def say_hello
     Grand_father.instance_method(:say_hello).bind(self).call
     puts "Son : Hello"
   end
end

However, as the weird construction indicates something might be wrong 
with this kind of design.  If you assume that the method actually had 
side effects on the instance's state and you leave out one class in the 
chain you likely end up with an instance in an inconsistent state.  In 
that case the design probably needs some work.

Btw, if Father does not define say_hello super will automatically call 
Grand_father's method.

Kind regards

	robert

-- 
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