Allows exclude shipment lines of computation of costs of payment type when compute is without taxes

__init__.py

@@ -3,9 +3,11 @@
 # copyright notices and license terms.
 from trytond.pool import Pool
 from sale import *
+from payment_type import *
 
 
 def register():
     Pool.register(
         Sale,
+        PaymentType,
         module='sale_payment_type_cost', type_='model')

payment_type.py

@@ -0,0 +1,30 @@
+# The COPYRIGHT file at the top level of this repository contains
+# the full copyright notices and license terms.
+from trytond.model import fields
+from trytond.pool import PoolMeta
+from trytond.pyson import Bool, Eval
+
+
+__all__ = ['PaymentType']
+__metaclass__ = PoolMeta
+
+
+class PaymentType:
+    __name__ = 'account.payment.type'
+    exclude_shipment_lines = fields.Boolean('Exclude Shipment Lines',
+        states={
+            'invisible': Bool(Eval('compute_over_total_amount')),
+                },
+        help='Excludes the shipment lines of computation of costs of this '
+            'payment type.')
+
+    @fields.depends('compute_over_total_amount')
+    def on_change_compute_over_total_amount(self):
+        try:
+            res = super(PaymentType,
+                self).on_change_compute_over_total_amount()
+        except AttributeError:
+            res = {}
+        if self.compute_over_total_amount:
+            res['exclude_shipment_lines'] = False
+        return res

payment_type.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0"?>
+<!-- The COPYRIGHT file at the top level of this repository contains the full
+copyright notices and license terms. -->
+<tryton>
+    <data>
+        <!-- account.payment.type -->
+        <record model="ir.ui.view" id="account_payment_type_view_form">
+            <field name="model">account.payment.type</field>
+            <field name="name">payment_type_form</field>
+            <field name="inherit"
+                ref="account_payment_type.account_payment_type_view_form"/>
+        </record>
+   </data>
+</tryton>

sale.py

@@ -47,9 +47,13 @@ class Sale:
                 continue
             setattr(line, key, value)
         if self.payment_type.compute_over_total_amount:
-            line.unit_price = (self.total_amount *
-                self.payment_type.cost_percent)
+            amount = self.total_amount
+        elif self.payment_type.exclude_shipment_lines:
+            amount = sum([l.amount
+                    for l in self.lines
+                    if not getattr(l, 'shipment_cost', False)
+                    ])
         else:
-            line.unit_price = (self.untaxed_amount *
-                self.payment_type.cost_percent)
+            amount = self.untaxed_amount
+        line.unit_price = (amount * self.payment_type.cost_percent)
         return line

tryton.cfg

@@ -3,3 +3,7 @@ version=3.4.0
 depends:
     sale_payment_type
     account_payment_type_cost
+extras_depend:
+    sale_shipment_cost
+xml:
+    payment_type.xml

view/payment_type_form.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0"?>
+<!-- The COPYRIGHT file at the top level of this repository contains the full
+copyright notices and license terms. -->
+<data>
+    <xpath expr="/form/group[@id='costs']" position="replace_attributes">
+        <group id="costs" colspan="4" col="10"/>
+    </xpath>
+    <xpath expr="/form/group/field[@name='compute_over_total_amount']"
+            position="after">
+        <label name="exclude_shipment_lines"/>
+        <field name="exclude_shipment_lines"/>
+    </xpath>
+</data>