title: How to configure a pg_search multisearch on associated models in Rails?
body: <p>I'm adding pg_search into a Rails app. I'm not completely understanding the configuration, and would appreciate a gentle nudge in the right direction.</p>
  
  <p>First, I already have a multi model site more or less set up and running on my app. But I want to extend it to also search on associated models.</p>
  
  <p>For example, I have Manufacturer, Car, Model classes. Currently if I search for "Ford", only the manufacturer is returned. I'd also like to return all the associated Cars (which belong to Manufacturer) and Models (which belong to Car).</p>
  
  <p>I can see how to do this as a scoped search</p>
  
  <pre><code>class Car
    pg_search_scope :manufactured_by, :associated_against =&gt; {
      :manufacturer =&gt; [:name]
    }
  end
  </code></pre>
  
  <p>But if I try to do this on a multisearch it doesn't work</p>
  
  <pre><code>class Car
    include PgSearch
    multisearchable :against =&gt; [:name], 
      :associated_against =&gt; {
          :manufacturer =&gt; [:name]
        }
  end
  </code></pre>
  
  <p>It doesn't generate an error, it simply doesn't pick up the associated records.</p>
  
  <p>I have a feeling I'm missing something fundamental in my understanding of how this all fits together. I'd really appreciate if someone could help me understand this, or point me towards a good source of info. I've been through the info on github and the related Railscast, but I'm still missing something.  </p>