Internal messaging in Rails

I'm using this tutorial to get internal messages working on my site: http://www.nov开发者_JAVA技巧awave.net/public/rails_messaging_tutorial.html

But, since my latest upgrade to Rails 3, I'm getting this error:

NoMethodError in MsgController#sendmsg
undefined method `each' for #<String:0xcc8acc0>

Application trace:

app/models/message.rb:16:in `prepare_copies'
app/controllers/msg_controller.rb:140:in `sendmsg'

The Message model:

class Message < ActiveRecord::Base
  belongs_to :author, :class_name => "User"
  has_many :message_copies
  has_many :recipients, :through => :message_copies
  before_create :prepare_copies

  attr_accessor  :to # array of people to send to
  attr_accessible :subject, :body, :to

  def prepare_copies
    return if to.blank?

    to.each do |recipient|
      recipient = User.find(recipient)
      message_copies.build(:recipient_id => recipient.id, :folder_id => recipient.inbox.id)
    end
  end
end

That tutorial seems a bit dated. It uses Rails 2.0 (and probably some equally old Ruby version).

Are you sure that to holds an Array (as indicated in your attr_accessor comment)? The error message seems to indicate that it is a String.

Did you previously have this code running under Ruby 1.8 (and, presumably, a version of Rails 2.3)?

In Ruby 1.8 you could send each to String instances and it would (by default) iterate on the lines of the string (actually it would split on $/ and iterate on the result).

In Ruby 1.9 you need to use each_line to iterate over the lines of a string.

to.each_line do |recipient|
  …
end

Seems you to is no anymore an Array but a String now. You problem semmes becomes from your controller and how you define your to accessor inside it.