From: Brian Candler <B.Candler@...>
Date: 2003-02-22T06:19:08+09:00
Subject: Re: Extending existing classes under mod_ruby... (and the "ruby way")

On Sat, Feb 22, 2003 at 03:23:01AM +0900, Frank Fejes wrote:
> class String
>     def is_valid_date?
>        <my test>
>     end
> end
> 
> Now I can call:
> 
> <do something> if entered_date.is_valid_date?
> 
> But that does not work with mod_ruby and I feel funny about extending
> such a fundamental class like String. ;)
> 
> So, what's the ruby way of handling this?  Thanks!

Perhaps a class method. This particular operation is not tied to a
particular object, but then if you wanted to do other operations on dates
(e.g. calculate the number of days between two dates) you could then have
instances representing a particular date.

  class MyDate
    def MyDate.is_valid?(str)  # test if a string is valid
      ...
    end
    def initialize(str)        # create a 'MyDate' object from string
      ...
    end
  end

  today = "2003-02-21"
  puts "hello" if MyDate.is_valid?(today)

Incidentally, you might want to look at date.rb in the Ruby standard
library, and date2 on RAA (I haven't used either)

Regards,

Brian.