[IMP] estate: add SQL and Python constraints

- Added SQL constraints:
  * Expected price must be strictly positive.
  * Selling price must be positive.
  * Offer price must be strictly positive.
  * Property tag name must be unique.
  * Property type name must be unique.

- Added Python constraint:
  * Ensure the selling price cannot be lower than 90% of the expected price
    (except when selling price is zero before offer validation).

Author: snrav-odoo

estate/__manifest__.py

@@ -7,12 +7,12 @@
     'license': 'LGPL-3',
     'description': 'Real estate purchase & sales',
     'data': [
+        'security/ir.model.access.csv',
         'views/estate_property_views.xml',
         'views/estate_property_type_views.xml',
         'views/estate_property_tag_views.xml',
         'views/estate_property_offer_views.xml',
-        'views/estate_property_menu.xml',
-        'security/ir.model.access.csv'
+        'views/estate_property_menu.xml'
         ],
     'application': True,
 }

estate/models/estate_property.py

@@ -1,11 +1,17 @@
 from dateutil.relativedelta import relativedelta
 from odoo import models, api, fields, exceptions
+from odoo.exceptions import ValidationError
 
 
 class EstateProperty(models.Model):
     _name = "estate.property"
     _description = "Real Estate Property"
-
+    _check_expected_price = models.Constraint(
+        "CHECK(expected_price > 0)", "Expected price must be strictly positive."
+    )
+    _check_selling_price = models.Constraint(
+        "CHECK(selling_price >= 0)", "Selling price must be positive."
+    )
     name = fields.Char(required=True)
     description = fields.Text()
     postcode = fields.Char()
@@ -86,3 +92,14 @@ def action_cancel_offer(self):
             else:
                 record.state = "cancelled"
         return True
+
+    @api.constrains("selling_price", "expected_price")
+    def _check_selling_price_percentage_criteria(self):
+        for record in self:
+            selling_price_percentage = (record.selling_price / record.expected_price) * 100
+            if selling_price_percentage >= 90 or selling_price_percentage == 0:
+                pass
+            else:
+                raise ValidationError(
+                    "The selling price cannot be lower then 90% of the expected price."
+                )

estate/models/estate_property_offer.py

@@ -5,7 +5,9 @@
 class EstatePropertyOffer(models.Model):
     _name = "estate.property.offer"
     _description = "Estate Property Offer"
-
+    _check_price = models.Constraint(
+        "CHECK(price > 0)", "Price of an offer must be positive"
+    )
     price = fields.Float()
     status = fields.Selection(
         selection=[("accepted", "Accepted"), ("refused", "Refused")], copy=False

estate/models/estate_property_tag.py

@@ -4,6 +4,7 @@
 class EstatePropertyTags(models.Model):
     _name = "estate.property.tag"
     _description = "Estate Property Tag"
-    _order = "name"
-
+    _check_tag_name = models.Constraint(
+        "UNIQUE(name)", "Property tag should be unique."
+    )
     name = fields.Char(required=True)

estate/models/estate_property_type.py

@@ -4,5 +4,7 @@
 class EstatePropertyType(models.Model):
     _name = "estate.property.type"
     _description = "Estate Property Type"
-
+    _check_type_name = models.Constraint(
+        "UNIQUE(name)", "Property type should be unique."
+    )
     name = fields.Char(required=True)