minor fix

wage_type.py

@@ -7,6 +7,7 @@ from trytond.transaction import Transaction
 from trytond.i18n import gettext
 from .exceptions import WageTypeValidationError
 from trytond.tools import lstrip_wildcard
+from trytond.pool import Pool
 
 STATES = {'readonly': Not(Bool(Eval('active')))}
 
@@ -29,9 +30,13 @@ class WageType(ModelSQL, ModelView):
             ('deduction', 'Deduction'),
             ], 'Definition', required=True)
     unit_price_formula = fields.Char('Unit Price Formula',
-            help='Python expression for eval(expr)')
+            help="""Python expression for eval(expr) \b
+            -salary: the salary employee \b
+            -minimum_salary: the salary minimum fixed """)
     expense_formula = fields.Char('Expense Formula',
-            help='Python expression for eval(expr)')
+            help="""Python expression for eval(expr) \b
+            -salary: the salary employee \b
+            -minimum_salary: the salary minimum fixed """)
     uom = fields.Many2One('product.uom', 'UOM', required=True)
     default_quantity = fields.Numeric('Default Quantity', digits=(16, 2))
     type_concept = fields.Selection([
@@ -132,6 +137,9 @@ class WageType(ModelSQL, ModelView):
         Compute a formula field with a salary value as float
         :return: A decimal
         '''
+        Configuration = Pool().get('staff.configuration')
+        configuration = Configuration(1)
+        minimum_salary = float(configuration.minimum_salary or 0)
         formula = getattr(self, formula)
         if not formula:
             return Decimal('0.0')