Question

I have two User objects existing_user, current_user, how should I traverse the User.attributes.keys and check if they are equal.

Answer 1

Probably something like this:

class User < ActiveRecord::Base

  # ...

  # untested, but the logic seems sound.
  def equals?(user)
    User.attributes.keys.each do |k|          
      return false unless self[k] == user[k]
    end
    true
  end

end

You could then call current_user.equals?(existing_user).