line: funktion für 'balance' + test

reconciliation: rec_name + test

line.py

@@ -5,7 +5,7 @@
 
 from decimal import Decimal
 from trytond.model import fields
-from trytond.pool import PoolMeta
+from trytond.pool import PoolMeta, Pool
 from trytond.pyson import Eval, Or, If
 from trytond.exceptions import UserError
 from trytond.i18n import gettext
@@ -106,6 +106,19 @@ class Line(metaclass=PoolMeta):
         result['quantity'] = line.quantity
         return result
 
+    @fields.depends('id', 'date', 'cashbook', \
+        '_parent_cashbook.id', 'reconciliation', \
+        '_parent_reconciliation.start_quantity',\
+        '_parent_reconciliation.state')
+    def on_change_with_quantity_balance(self, name=None):
+        """ get quantity-balance
+        """
+        Line2 = Pool().get('cashbook.line')
+        return Line2.get_balance_of_line(self,
+            field_name='quantity',
+            credit_name='quantity_credit',
+            debit_name='quantity_debit')
+
     @fields.depends('quantity', 'amount', 'currency_digits', 'quantity_digits')
     def on_change_with_asset_rate(self, name=None):
         """ get rate