[IMP] delivery: set default custom code on packaging type

addons/delivery/models/delivery_carrier.py

@@ -26,6 +26,7 @@ class DeliveryCarrier(models.Model):
        <my_provider>_send_shipping
        <my_provider>_get_tracking_link
        <my_provider>_cancel_shipment
+       _<my_provider>_get_default_custom_package_code
        (they are documented hereunder)
     '''
 
@@ -183,6 +184,16 @@ class DeliveryCarrier(models.Model):
             except psycopg2.Error:
                 pass
 
+    def _get_default_custom_package_code(self):
+        """ Some delivery carriers require a prefix to be sent in order to use custom
+        packages (ie not official ones). This optional method will return it as a string.
+        """
+        self.ensure_one()
+        if hasattr(self, '_%s_get_default_custom_package_code' % self.delivery_type):
+            return getattr(self, '_%s_get_default_custom_package_code' % self.delivery_type)()
+        else:
+            return False
+
     # ------------------------------------------------ #
     # Fixed price shipping, aka a very simple provider #
     # ------------------------------------------------ #

addons/delivery/models/product_packaging.py

@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
-from odoo import models, fields
+from odoo import models, fields, api
 
 
 class ProductPackaging(models.Model):
@@ -20,3 +20,11 @@ class ProductPackaging(models.Model):
         ('positive_length', 'CHECK(length>=0)', 'Length must be positive'),
         ('positive_max_weight', 'CHECK(max_weight>=0.0)', 'Max Weight must be positive'),
     ]
+
+    @api.onchange('package_carrier_type')
+    def _onchange_carrier_type(self):
+        carrier_id = self.env['delivery.carrier'].search([('delivery_type', '=', self.package_carrier_type)], limit=1)
+        if carrier_id:
+            self.shipper_package_code = carrier_id._get_default_custom_package_code()
+        else:
+            self.shipper_package_code = False