[FIX] crm_won_restrict_per_stage: Add ValidationError to onchange to …

…prevent display incorrect UX changes

TT49558

crm_won_restrict_per_stage/models/crm_lead.py

@@ -1,7 +1,7 @@
 # Copyright 2024 Tecnativa - Carolina Fernandez
 # License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html)
 
-from odoo import _, fields, models
+from odoo import _, api, fields, models
 from odoo.exceptions import ValidationError
 
 
@@ -10,6 +10,23 @@ class CrmStage(models.Model):
 
     show_won_button = fields.Boolean(related="stage_id.show_won_button")
 
+    @api.onchange("stage_id")
+    def _onchange_stage_id(self):
+        """Do it this way for avoiding a UI glitch if we let act
+        the exception in the write, as the stage is changed in the
+        interface, but the message appears and the record is kept
+        unsaved.
+        """
+        for item in self:
+            if (
+                item != item._origin
+                and item.stage_id.is_won
+                and not item._origin.stage_id.show_won_button
+            ):
+                raise ValidationError(
+                    _("You can't change to this stage from the current stage.")
+                )
+
     def write(self, vals):
         for rec in self:
             if vals.get("stage_id"):

crm_won_restrict_per_stage/tests/test_crm_lead.py

@@ -2,6 +2,7 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html)
 
 from odoo.exceptions import ValidationError
+from odoo.tests import Form
 from odoo.tests.common import TransactionCase
 
 
@@ -13,11 +14,17 @@ def setUpClass(cls):
         cls.stage_new = cls.env.ref("crm.stage_lead1")
         cls.stage_won = cls.env.ref("crm.stage_lead4")
 
-    def test_change_crm_stage_won_without_show_button(self):
+    def test_change_crm_stage_won_without_show_button_01(self):
         self.stage_new.show_won_button = False
         with self.assertRaises(ValidationError):
             self.crm_lead.stage_id = self.stage_won
 
+    def test_change_crm_stage_won_without_show_button_02(self):
+        self.stage_new.show_won_button = False
+        lead_form = Form(self.crm_lead)
+        with self.assertRaises(ValidationError):
+            lead_form.stage_id = self.stage_won
+
     def test_change_crm_stage_to_won_with_show_button(self):
         self.stage_new.show_won_button = True
         self.crm_lead.stage_id = self.stage_won