/** * Return the categories of the campaigns that were donated to. * * @return string * @access public * @since 1.4.2 */ public function get_campaign_categories_for_donation($value) { if (!$this->has_valid_donation()) { return $value; } $categories = $this->donation->get_campaign_categories_donated_to('campaign_category', array('fields' => 'names')); return implode(', ', $categories); }