If you're working on a webapp these days, chances are you've needed to build an activity feed or two. There are a few approaches floating around — mostly involving observers. Not a fan of observers and needing something reusable, we built our own.

To get started with timeline_fu, run the generator.

script/generate timeline_fu && rake db
                                                        :migrate

You'll get a model called TimelineEvent and the necessary migration. Then, anywhere you need to fire a timeline event, simply declare it.

class Post
  belongs_to 
                                                        :creator, 
                                                        :class_name => 
                                                        "User"
                                                      

  fires 
                                                        :created, 
                                                        :actor => 
                                                        :creator,
                  
                                                        :on    => 
                                                        :create
end