firs commit

sale.py

@@ -0,0 +1,46 @@
+from trytond.pool import Pool, PoolMeta
+from trytond.model import ModelView, fields
+from trytond.exceptions import UserError
+
+
+class Sale(metaclass=PoolMeta):
+    "Sale Fast Food"
+    __name__ = 'sale.sale'
+
+    pizza_number = fields.Integer("Number pizza")
+    
+    @classmethod
+    def __setup__(cls):
+        super(Sale, cls).__setup__()
+        cls._buttons.update({
+            'add_pizza': {},
+        })
+
+    @classmethod
+    def default_pizza_number(cls):
+        return 0
+
+    @classmethod
+    @ModelView.button
+    def add_pizza(cls, records):
+        for record in records:
+            record.pizza_number +=1
+            record.save()
+
+            
+class Line(metaclass=PoolMeta):
+    "Sale Line Fast Food"
+    __name__ = 'sale.line'
+
+    pizza = fields.Integer("Pizza")
+
+
+    @fields.depends('product', 'unit', 'sale',
+        '_parent_sale.party', '_parent_sale.invoice_party',
+                    '_parent_sale.pizza_number',
+        methods=['compute_taxes', 'compute_unit_price',
+            'on_change_with_amount'])
+    def on_change_product(self):
+        super(Line, self).on_change_product()
+        if self.product.pizza:
+            self.pizza = self.sale.pizza_number