public function ajax_wpl_ebay_store_categories() { $default_account_id = get_option('wplister_default_account_id'); $account_id = isset($_REQUEST['account_id']) ? intval($_REQUEST['account_id']) : $default_account_id; $store_categories = EbayCategoriesModel::getEntireStoreCategoryTree(0, $account_id); // check if callback parameter is set if (isset($_REQUEST['callback'])) { // return JSONP header('content-type: application/javascript; charset=utf-8'); echo $_REQUEST['callback'] . '(' . json_encode($store_categories) . ')'; } else { // return plain JSON header('content-type: application/json; charset=utf-8'); echo json_encode($store_categories); } exit; }