Question

I have the following models.

class Post < ActiveRecord::Base
  has_many :timeline_items, :as=>:subject

  define_index do
    ....?
  end
end

class TimelineItem < ActiveRecord::Base
  belongs_to :subject, :polymorphic=>true
  belongs_to :actor, :polymorphic=>:true
end

I want to get all the posts belonging to specific actors with thinking-sphinx.

In ActiveRecord I would do like

Post.where('timeline_items.actor_type = "User" AND timeline_items.actor_id IN [1,2,3]).includes(:timeline_items)

My question is what indexes have to define and what query have to use to get the same results with thinking-sphinx?

Update
However I also need to filter the posts by different actor types like:
Post.where('timeline_items.actor_type = "Group" AND timeline_items.actor_id IN [1,2,3]).includes(:timeline_items)

Answer 1

Give the following a try:

define_index do
  # ...
  has timeline_items.actor.id, :as => :actor_ids
end

And then for searching:

Post.search 'foo', :with => {:actor_ids => [1,2,3]}

As detailed in the comments, if you need to filter on a specific class’s values in those polymorphic associations, then you’re going to need to create another association for just that class. This is because Sphinx has no concept of hashes/key-value pairs, and so can’t track which ids belongs to which classes.

Once you have that new association in place, then add an attribute for that much like above – perhaps like this:

has user_timeline_items.actor.id, :as => :user_actor_ids