Rails 3 add virtual attribute dynamically

Question

My setup: Rails 3.0.9, Ruby 1.9.2

I have my reasons for doing this but what I need is a way to add a virtual attribute to an activerecord resultset dynamically. That means I am not using attr_accessor in the model and instead wish to dynamically add virtual attributes to a resultset.

For example,

users = User.all
#a user has following attributes: name, email, password

What I like to do is say add (without using attr_accessor) a virtual attribute status to users, is that possible?

Answer 1

You should do this:

users.each do |user|
  user.instance_eval do
    def status
      instance_variable_get("@status")
    end        
    def status=(val) 
      instance_variable_set("@status",val)
    end
  end
end