ThinkingSphinx - Search through has_many association

Question

I have a relationship between two models, Idea and Iteration . Each idea can have many iterations. The models looks like this;

# idea.rb
has_many :iterations, dependent: :destroy

# I also use with: :real_time 
after_save ThinkingSphinx::RealTime.callback_for(:idea)

# iteration.rb
belongs_to :idea
after_save ThinkingSphinx::RealTime.callback_for(:idea, [:idea])

My indexes for Idea looks like this:

ThinkingSphinx::Index.define :idea, :with => :real_time do
  [...]
  indexes iterations.title, as: :iteration_titles
  indexes iterations.description, as: :iteration_descriptions
  has iterations.id, :as => :iteration_ids, type: :integer
  [...]
end

And I search like this:

@ideas = @user.ideas.search  ThinkingSphinx::Query.escape(params[:search]),
  :with => {:team_id => @teams.collect(&:id)},
  :page     => params[:page],
  :per_page => 10,
  :order    => 'created_at DESC'

Currently, searching for either Iteration title or description returns 0 hits. And I have performed:

rake ts:rebuild
rake ts:regenerate
rake ts:index

Have I missed something?

Answer 1

One of the differences between real-time indices and SQL-backed indices is that with SQL-backed indices, you refer to associations and columns in your index definition, but with real-time indices, you refer to methods.

And while iterations is an instance method within an idea , title , description and id are not methods on the object returned by iterations .

The easiest way to work through this has two parts. Firstly, add instance methods to Idea that return the data you want for the iteration-related fields and attributes:

def iteration_titles
  iterations.collect(&:title).join(' ')
end

def iteration_descriptions
  iterations.collect(&:description).join(' ')
end

def iteration_ids
  iterations.collect &:id
end

And then use those methods in your index definition:

indexes iteration_titles, iteration_descriptions
has iteration_ids, :type => :integer, :multi => true

And then, run rake ts:regenerate to get it all set up ( ts:rebuild and ts:index have no meaning for real-time indices).