[FIX] models: implement change_default behavior for fields

The behavior is no longer implemented by the web client.  Implement it
server-side as part of the onchange mechanism, simply by defining onchange
methods for the fields that have the flag.

odoo/addons/test_new_api/models.py

@@ -286,7 +286,7 @@ class Foo(models.Model):
     _name = 'test_new_api.foo'
 
     name = fields.Char()
-    value1 = fields.Integer()
+    value1 = fields.Integer(change_default=True)
     value2 = fields.Integer()
 
 

odoo/addons/test_new_api/tests/test_onchange.py

@@ -231,6 +231,28 @@ class TestOnChange(common.TransactionCase):
                       for user in discussion.participants + demo],
         )
 
+    def test_onchange_default(self):
+        """ test the effect of a conditional user-default on a field """
+        Foo = self.env['test_new_api.foo']
+        field_onchange = Foo._onchange_spec()
+        self.assertTrue(Foo._fields['value1'].change_default)
+        self.assertEqual(field_onchange.get('value1'), '1')
+
+        # create a user-defined default based on 'value1'
+        self.env['ir.values'].set_default('test_new_api.foo', 'value2', 666, condition='value1=42')
+
+        # setting 'value1' to 42 should trigger the change of 'value2'
+        self.env.invalidate_all()
+        values = {'name': 'X', 'value1': 42, 'value2': False}
+        result = Foo.onchange(values, 'value1', field_onchange)
+        self.assertEqual(result['value'], {'value2': 666})
+
+        # setting 'value1' to 24 should not trigger the change of 'value2'
+        self.env.invalidate_all()
+        values = {'name': 'X', 'value1': 24, 'value2': False}
+        result = Foo.onchange(values, 'value1', field_onchange)
+        self.assertEqual(result['value'], {})
+
     def test_onchange_one2many_value(self):
         """ test the value of the one2many field inside the onchange """
         discussion = self.env.ref('test_new_api.discussion_0')

odoo/models.py

@@ -573,6 +573,7 @@ class BaseModel(object):
         def is_onchange(func):
             return callable(func) and hasattr(func, '_onchange')
 
+        # collect onchange methods on the model's class
         cls = type(self)
         methods = defaultdict(list)
         for attr, func in getmembers(cls, is_onchange):
@@ -581,6 +582,17 @@ class BaseModel(object):
                     _logger.warning("@onchange%r parameters must be field names", func._onchange)
                 methods[name].append(func)
 
+        # add onchange methods to implement "change_default" on fields
+        def onchange_default(field, self):
+            value = field.convert_to_write(self[field.name], self)
+            condition = "%s=%s" % (field.name, value)
+            defaults = self.env['ir.values'].get_defaults_dict(self._name, condition)
+            self.update(defaults)
+
+        for name, field in cls._fields.items():
+            if field.change_default:
+                methods[name].append(functools.partial(onchange_default, field))
+
         # optimization: memoize result on cls, it will not be recomputed
         cls._onchange_methods = methods
         return methods