[ADD] - new module Product Contract Variable Quantity

product_contract_variable_quantity/models/product_template.py

@@ -0,0 +1,31 @@
+# Copyright 2018 ACSONE SA/NV
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+from odoo import api, fields, models
+
+
+class ProductTemplate(models.Model):
+    _inherit = 'product.template'
+
+    qty_type = fields.Selection(
+        selection=[
+            ('fixed', 'Fixed quantity'),
+            ('variable', 'Variable quantity'),
+        ],
+        required=False,
+        default='fixed',
+        string="Qty. type",
+    )
+    qty_formula_id = fields.Many2one(
+        comodel_name="contract.line.qty.formula", string="Qty. formula"
+    )
+
+    @api.onchange('is_contract')
+    def _change_is_contract(self):
+        """ Clear the relation to contract_template_id when downgrading
+        product from contract
+        """
+        super(ProductTemplate, self)._change_is_contract()
+        if not self.is_contract:
+            self.qty_type = False
+            self.qty_formula_id = False