Improvements to invoice

modules/invoice/classes/Invoicable.php

@@ -0,0 +1,16 @@
+<?php defined('SYSPATH') or die('No direct access allowed.');
+
+/**
+ * This interface ensures that all invoice processing objects have the right methods
+ *
+ * @package    Invoice
+ * @category   Interface
+ * @author     Deon George
+ * @copyright  (c) 2009-2013 Open Source Billing
+ * @license    http://dev.osbill.net/license.html
+ */
+interface Invoicable {
+	// Render the line item for an invoice
+	public function invoice_line();
+}
+?>