thinking-sphinx has_many :through relationships

I've got a many-to-many relationship between ledger and staff and would like to use Thinking-Sphinx (TS) to search ledgers which the current_staff member owns.

In Rails 3 console I've tried the following

> Ledger.search 'test', :include => :staff_ids, :with => {:staff_ids => 1}
Returns []
> Ledger.search 'test', :include => :staff_id,  :condition => {:staff_id => 1}
Returns ledgers which do not belong to staff member with id 1.

Ledger Model

class Ledger < ActiveRecord::Base
  has_many :employees
  has_many :staff, :through => :employees

  define_index do
    indexes :name
#    indexes staff.id, :as => :staff_id # many to many relationship.
    has staff(:id), :as => :staff_ids # many to many relationship.    

    set_property :delta => true
  end
end

Staff Model

class Staff < ActiveRecord::Base
  has_many :employees
  has_many :ledgers, :throu开发者_如何学编程gh => :employees

  define_index do
    indexes username
    indexes surname
    indexes firstname

    set_property :delta => true    # http://freelancing-god.github.com/ts/en/deltas.html    
  end
end

I have got the following inflection setup

  inflect.uncountable %w( staff )

I've tried indexes and has in my Ledger model, rebuilding and restarting TS after each change to indexes.

Update1:

I'm very close. If I do a 'rake ts:reindex' then restart me rails server, my search on ledgers (associated to the current_staff) works fine:

@results = Ledger.search params[:search], :include =>:staff_id, :conditions =>{:staff_id => current_staff.id}

It's almost like I have to have a delta on my has_many :through model, is this correct?

Update 2:

I've started to play around with Delta's and associations as in the thinking-sphinx documentation. Still doesn't seem to work though.

Here is what I've put in my Ledger model:

  after_save :set_staff_delta_flag
  ...
  private

  def set_staff_delta_flag
    staff.delta = true
    staff.save
  end

I get the following error when trying to add a new ledger:

NoMethodError (undefined method `delta=' for #<Class:0x00000001516340>):
  app/models/ledger.rb:19:in `set_staff_delta_flag'
  app/controllers/ledgers_controller.rb:24:in `create'

I found the answer!

I have to set the staff delta flag after the save, but as I have multiple I have to do that for each staff.

Here is my ledger model

class Ledger < ActiveRecord::Base
  has_many :employees
  has_many :staff, :through => :employees

  after_save :set_staff_delta_flag

  define_index do
    indexes :name
    indexes staff.id, :as => :staff_id # many to many relationship.
    set_property :delta => true
  end

  private

  def set_staff_delta_flag
    staff.map{ |s| s.update_attribute("delta", true)}
  end
end

Now in my Rails app if I add a new ledger for a current staff member and use the following I can see the new ledger in the search results.

@results = Ledger.search params[:search], :include =>:staff_id, :conditions =>{:staff_id => current_staff.id}

If there is a better way to do this let me know.

It resolved itself for me when I added attr_accessor :delta to the models that I was delta indexing.