Require incoterm on sale for EU countries if intratstat is extended

modules/account_stock_eu/__init__.py

@@ -4,7 +4,7 @@
 from trytond.pool import Pool
 
 from . import (
-    account, account_stock_eu, carrier, company, country, customs, stock)
+    account, account_stock_eu, carrier, company, country, customs, sale, stock)
 
 __all__ = ['register']
 
@@ -38,6 +38,10 @@ def register():
         stock.Move_Incoterm,
         module='account_stock_eu', type_='model',
         depends=['incoterm'])
+    Pool.register(
+        sale.Sale_Incoterm,
+        module='account_stock_eu', type_='model',
+        depends=['sale', 'incoterm'])
     Pool.register(
         stock.Move_Consignment,
         module='account_stock_eu', type_='model',

modules/account_stock_eu/sale.py

@@ -0,0 +1,48 @@
+# This file is part of Tryton.  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.modules.account.exceptions import FiscalYearNotFoundError
+from trytond.pool import Pool, PoolMeta
+
+
+class Sale_Incoterm(metaclass=PoolMeta):
+    __name__ = 'sale.sale'
+
+    @property
+    @fields.depends('company')
+    def _incoterm_required(self):
+        pool = Pool()
+        FiscalYear = pool.get('account.fiscalyear')
+
+        required = super()._incoterm_required
+
+        if not required and self.company and self.company.incoterms:
+            if (self.warehouse and self.warehouse.address
+                    and self.shipment_address):
+                try:
+                    fiscalyear = FiscalYear.find(
+                        self.company.id,
+                        date=self.sale_date)
+                except FiscalYearNotFoundError:
+                    pass
+                else:
+                    if fiscalyear.intrastat_extended:
+                        from_country = self.warehouse.address.country
+                        if from_country:
+                            from_europe = from_country.is_member(
+                                'country.organization_eu',
+                                self.sale_date)
+                        else:
+                            from_europe = None
+                        to_country = self.shipment_address.country
+                        if to_country:
+                            to_europe = to_country.is_member(
+                                'country.organization_eu',
+                                self.sale_date)
+                        else:
+                            to_europe = None
+                    required = (
+                        (from_country != to_country)
+                        and not (from_europe and to_europe))
+        return required