From: Jason Voegele <jason@...>
Date: 2004-04-06T21:18:26+09:00
Subject: Re: object.@attribute

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On Monday 05 April 2004 5:26 pm, Hal Fulton wrote:
>      attr_reader :number     # Let outside world read this value
>      attr_writer :number     #  "     "       "  set it
>      attr_accessor :number   #  "     "       "  read or set it
>
> In practice, I've never used attr_writer. It's hard to imagine
> something useful being write-only and not readable. (Insert
> Perl wisecrack here.)

Hehe...I'll avoid the Perl wisecrack, but I can think of a couple scenarios 
where attr_writer might be useful:

1) True write-only data, such as a password.  For example, you might have 
password=(pwd) to set the password, and verify_password(pwd) to compare the 
password to a given string, but no password reader method.  This is 
especially useful if you store passwords in hashed form so that they cannot 
be retrieved once hashed.

2) You might want to use a standard attr_writer generated writer method, but 
provide a custom reader method.  I do this all of the time with boolean 
attributes, so I can add the '?' to the end of the reader method.

- -- 
Jason Voegele
Sodd's Second Law:
	Sooner or later, the worst possible set of circumstances is
	bound to occur.
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