From: Matt Mencel <MR-Mencel@...>
Date: 2012-05-16T23:25:22+09:00
Subject: Passing attributes to initialize

Hi,

I'm not an OOP person.  Most of the Ruby I write is just scripts and such.  I've found a good place to start using real Class objects though and am having a hard time getting my head around it.

I have this class.  The @members attribute is an array of several 5 digit numbers (could be between 1 and 10 values in the array).  I want to be able to find objects in the Class by using one of the numbers.

class Crosslisting
  attr_accessor :members, :title, :id
 
  def initialize(members, name='', id='')
    @members = members 
    @name = name
    @id = id
  end

  def self.find_by_member(member)
    found = nil
    ObjectSpace.each_object(Crosslisting) { |o|
      found = o if o.members.include?(member)
    }
    found
  end
end

members = ['12345','67890']
my_obj = Crosslisting.new(members)
ap Crosslisting.find_by_member('12345')

# OUTPUT USING AWESOME_PRINT GEM
#<Crosslisting:0x00e77410
    attr_accessor :id = "",
    attr_accessor :members = [
        [0] "12345",
        [1] "67890"
    ],
    attr_accessor :name = ""
>


This seems to work ok.  Am I doing it right or is there a better way?  I tried to figure out how to use 'def initialize(*args)' instead of naming all the attributes, but I'm not currently smart enough to make it work apparently.

I thought about trying to use Hashes and symbols...maybe that's a better way or maybe not....but again haven't figured out how to make it work....something like...
my_obj = Crosslisting.new(:member => members)


Thanks,
Matt