From: Satsou Sa <moshimoshi.here@...>
Date: 2010-12-31T03:02:06+09:00
Subject: Re: How to hook a callback through inheritance

Josh Cheek wrote in post #971483:
> The problem is that before_laughing is being invoked as a class method
> on
> Lol. So when you say "before_laughing :downcase_please", you aren't
> setting
> @before_laughing on instances of Lol, but rather on Lol itself.

Okay.

> I suppose one way to do this is to leave the instance var on the
> class, then just ask the class for its contents and execute them
> the same way.

Using your code, I have the same result then Mon_Ouie, with one less
method in the code and no errors when a callback isn't called. It's just
so cool.

> With this implementation, that means you can't add callbacks
> for individual objects, though.

However, I am not sure to understand this point.  I believe I can do it.
Here I tried to add different callbacks on different classes (and every
thing is working find):

>> class Lol < Lmao
>>   before_laughing :downcase_please
>>
?>   def downcase_please
>>     @str.downcase!
>>   end
>> end
=> nil
>>
?> a = Lol.new
=> #<Lol:0x101f11448 @str="HAHAHAHAHAHHAHAHAH">
>> a.laughing
=> "hahahahahahhahahah"
>>
?> class Lool < Lmao
>>   before_laughing :add_ok
>>
?>   def add_ok
>>     @str.concat("_ok")
>>   end
>> end
=> nil
>>
?> b = Lool.new
=> #<Lool:0x101ee9448 @str="HAHAHAHAHAHHAHAHAH">
>> b.laughing
=> "HAHAHAHAHAHHAHAHAH_ok"
>>
?> class Loool < Lmao
>>   before_laughing :add_ok, :downcase_please
>>
?>   def add_ok
>>     @str.concat("_ok")
>>   end
>>
?>   def downcase_please
>>     @str.downcase!
>>   end
>> end
=> nil
>>
?> c = Loool.new
=> #<Loool:0x101eb4310 @str="HAHAHAHAHAHHAHAHAH">
>> c.laughing
=> "hahahahahahhahahah_ok"

But if I understand correctly, I can not do so by class instance...
Well, okay.  For my needs, it's just perfect anyway.  Thank you!!

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