Add reverse M2M field invoice_line <-> sale_line

sale_usability_extension/__init__.py

@@ -1,3 +1,4 @@
-# -*- encoding: utf-8 -*-
+# -*- coding: utf-8 -*-
 
 from . import sale
+from . import account_invoice

sale_usability_extension/account_invoice.py

@@ -0,0 +1,32 @@
+# -*- coding: utf-8 -*-
+##############################################################################
+#
+#    Sale Usability Extension module for Odoo
+#    Copyright (C) 2015 Akretion (http://www.akretion.com)
+#    @author Alexis de Lattre <alexis.delattre@akretion.com>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+
+from openerp import models, fields
+
+
+class AccountInvoiceLine(models.Model):
+    _inherit = 'account.invoice.line'
+
+    # reverse of the native M2M invoice_lines field on sale.order.line
+    sale_line_ids = fields.Many2many(
+        'sale.order.line', 'sale_order_line_invoice_rel', 'invoice_id',
+        'order_line_id', 'Sale Order Lines', readonly=True)