options inheritance

Question

Hi there.

I have a plugin module that extends the AR with a before_save callback to log all changes made into a relating acts_as_commentable comment. This works fine.

However, I want to add more details to the comment such as who made the change etc. I have made a couple of fields available to the model instance log_message and log_owner. The problem seems to be that my local variable options doesn't get inherited through the class_eval statement.

This is my code:

options = { :add_to_accessible => true, :owner_model => "User" }
attr_accessor :log_message, :log_owner, :log_options
attr_accessible :log_message, :log_owner, :log_options if options[:add_to_accessible] # This inherits the options fine.
# Before save goes here...
class_eval do 
  def log_changes_to_comments
    self.changes.each do |attr, values|
      # Do something with comment here...
      comment << options[:owner_model].classify.constantize.find(self.log_owner).name if self.log_owner
      # Do more with comment here...
    end
  end
end

Now, specifically the problem arises in: comment << options[:owner_model].classify.constantize which raises an error saying that the options variable doesn't exist.

How can I make sure that this variable is inherited?