title: Algolia Search PHP API Retrieve ObjectIDs
body: <p>I'm using algolia search's php API to perform a name search.  I would like for it to only return the objectIDs because I want to filter down the matches based on additional (external) criteria.  I added the attributesToRetrieve parameter to the search() both as a string and as an array, but it still returns everything.</p>
  
  <p>Any ideas?  Thanks!</p>
  
  <pre><code>$index-&gt;search('value', array("attributesToRetrieve" =&gt; "objectID"));  
  </code></pre>
  
  <p>OR</p>
  
  <pre><code> $index-&gt;search('value', array("attributesToRetrieve" =&gt; array("objectID")));  
  </code></pre>