module Publisher
  extend self

  def broadcast_event(event_name, payload={})
    if block_given?
      ActiveSupport::Notifications.instrument(event_name, payload) do
        yield
      end
    else
      ActiveSupport::Notifications.instrument(event_name, payload)
    end
  end

end

# Usage
if user.save
  Publisher.broadcast_event('user.created', user: user)
end

# Usage with block
def create_user(params)
  user = User.new(params)

  Publisher.broadcast_event('user.created', user: user) do
    User.save!
    # do some more important stuff here
  end
end