Add round_price

We add a common method to round prices that are stored using the price digits.
It is useless to use the digits from the field because it can not be changed in
any other way than by configuration.

issue9146
review299521002

CHANGELOG

@@ -1,3 +1,4 @@
+* Add round_price
 * Make product code unique
 * Add code to template as variant prefix code
 * Hide product fields inherited from template when empty

__init__.py

@@ -6,10 +6,10 @@ from . import uom
 from . import category
 from . import product
 from . import configuration
-from .product import price_digits
+from .product import price_digits, round_price
 from .uom import uom_conversion_digits
 
-__all__ = [price_digits, uom_conversion_digits]
+__all__ = [price_digits, round_price, uom_conversion_digits]
 
 
 def register():

product.py

@@ -26,7 +26,7 @@ from trytond.modules.company.model import (
 from .exceptions import InvalidIdentifierCode
 
 
-__all__ = ['price_digits', 'TemplateFunction']
+__all__ = ['price_digits', 'round_price', 'TemplateFunction']
 logger = logging.getLogger(__name__)
 
 TYPES = [
@@ -42,6 +42,12 @@ COST_PRICE_METHODS = [
 price_digits = (16, config.getint('product', 'price_decimal', default=4))
 
 
+def round_price(value, rounding=None):
+    "Round price using the price digits"
+    return value.quantize(
+        Decimal(1) / 10 ** price_digits[1], rounding=rounding)
+
+
 class Template(
         DeactivableMixin, ModelSQL, ModelView, CompanyMultiValueMixin):
     "Product Template"