How do I create a facebook style news feed in ruby on rails?

Question

I am trying to fuse to objects into a single stream.

I created a new model and controller called Newsfeed. I have it so that newsfeed has_many :messages and has_many

Answer 1

I'm sure this can be streamlined from it's ghetto-polymorphism, but it works for me, and I had an identical struggle with the "how do I combine all these model results?!"

I use a separate model, like you, and an observer:

class NewsfeedObserver < ActiveRecord::Observer

  observe Message, Image

  def after_save(object)
    @item = Newsfeed.create(
              :item_id => object.id, 
              :item_type => object.class.to_s
    )
  end
end

Then in the Newsfeed model you can pull and collate as you like:

def self.get_items
  item_list = []
  items = find(:all, :order => "created_at DESC", :limit => 30)
  items.collect{ |i| i.item_type.constantize.find(i.item_id) }
end

Then just pull them and display in your view however you like.

#Controller
def index
  @feed = Newsfeed.get_items
end

Moving forward I will probably start to pack more into the stream-tracking model in order to save hits on the other tables, but hopefully you get the idea.