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Re: super respondsToSelector

Subject: Re: super respondsToSelector
From: Ken Thomases <email@hidden>
Date: Sat, 31 May 2008 02:58:07 -0500
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On May 31, 2008, at 2:43 AM, j o a r wrote:

On May 31, 2008, at 12:23 AM, Michael Ash wrote:
Assume the following class hierarchy:
A <- B <- C <- D <- E
In the implementation of B, you write [self superclass]. Now your
method executes with self set to an instance of E. What do you get?
I would propose that you should re-examine your design if you find that to be a problem in practice:

<http://en.wikipedia.org/wiki/Code_smell>

Using [self superclass] is wrong. The hierarchy with five levels may or may not be a problem, but [self superclass] is still wrong even in a hierarchy with 3 levels (even if "A" is NSObject, as is typical).

If your class may be subclassed, then [[self superclass] instancesRespondToSelector:aSelector] may blow up in your face.

-Ken

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References:
	>super respondsToSelector (From: Russ McBride <email@hidden>)
	>Re: super respondsToSelector (From: Ken Thomases <email@hidden>)
	>Re: super respondsToSelector (From: "Michael Ash" <email@hidden>)
	>Re: super respondsToSelector (From: j o a r <email@hidden>)
	>Re: super respondsToSelector (From: "Michael Ash" <email@hidden>)
	>Re: super respondsToSelector (From: j o a r <email@hidden>)

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