I need to pass extra arguments to factory girl to be used in a callback. Something like this (but more complex really):

Factory.define :blog do |blog|
  blog.name "Blah"

  blog.after_create do |blog|
    blog.posts += sample_posts
    blog.save!
  end
end

and then create it with something like this:

Factory.create(:blog, :sample_posts => [post1, post2])

Any ideas how to do it?