gistfile1.rb

# This playing about lead to the following plugin:
#   http://github.com/craigw/callback_after_commit/tree/master
# use that instead.

module TransactionCommitCallback
  def self.included(base)
    base.send(:alias_method, :transaction_without_callbacks,
                             :transaction)
  end

  def transaction(*args)
    transaction_without_callbacks(*args)
    run_callbacks :after_commit
  end
end

ActiveRecord::Base.send(:define_callbacks, :after_commit)
ActiveRecord::ConnectionAdapters::DatabaseStatements.send(:include, TransactionCommitCallback)