Custom lithium finder

gistfile1.php

<?php
// Create a finder for popular tags
static::finder('popular', function($self, $params, $chain) { 
  $params['options']['joins'] = array(new Query(array(
    'source' => 'candidate_tags',
    'constraint' => array ('Tag.id' => 'candidate_tags.tag_id'),
    'group' => 'tag_id',
  )));
  $params['options']['fields'] = array('tag_id as id', 'name', 'client_id', 'count(tag_id) as theCount');
  $params['options']['order'] = 'theCount DESC';
  $params['options']['group'] = 'GROUP BY candidate_tags.tag_id';
  return $chain->next($self, $params, $chain);
});
?>