Ticket #3148: django-modelfield-getter-setters.diff

django/db/models/base.py

@@ -208 +208 @@
         else:
             setattr(cls, name, value)
 
+        # Add properties assigned via getter, setter and deleter field
+        # decorators
+        if hasattr(value, '_property') and value._property:
+            setattr(cls, name, property(**value._property))
+            del(value._property)
+
     def _prepare(cls):
         """
         Creates some methods once self._meta has been populated.

django/db/models/fields/__init__.py

@@ -97 +97 @@
             self.creation_counter = Field.creation_counter
             Field.creation_counter += 1
 
+        self._property = {} #  stores kwargs for property ('fget', 'fset', 'fdel')
+
     def __cmp__(self, other):
         # This is needed because bisect does not take a comparison function.
         return cmp(self.creation_counter, other.creation_counter)
@@ -148 +150 @@
         return self._unique or self.primary_key
     unique = property(unique)
 
+    def setter(self, f):
+        self._property['fset'] = f
+
+    def getter(self, f):
+        self._property['fget'] = f
+
+    def deleter(self, f):
+        self._property['fdel'] = f
+
     def set_attributes_from_name(self, name):
         self.name = name
         self.attname, self.column = self.get_attname_column()

tests/regressiontests/model_fields/tests.py

@@ -7 +7 @@
 from django.core.exceptions import ValidationError
 
 from models import Foo, Bar, Whiz, BigD, BigS, Image
+from models import FooGetSet
 
 try:
     from decimal import Decimal
@@ -144 +145 @@
         bs = BigS.objects.create(s = 'slug'*50)
         bs = BigS.objects.get(pk=bs.pk)
         self.assertEqual(bs.s, 'slug'*50)
+
+class FieldProperties(django.test.TestCase):
+    def test_get_set(self):
+        """
+        Test basic getter and setter functionality of a SlugField
+        """
+        f = FooGetSet( s = "test" )
+        self.assertEqual(f.s, "test")
+        f.s = "test2"
+        self.assertEqual(f.s, "test2")
+
+        def set_non_acceptable():
+            f.s = "not_acceptable"
+        self.assertRaises(ValueError, set_non_acceptable)
+        self.assertEqual(f.s, "test2")
+
+        f.save()
+        f = FooGetSet.objects.get(pk=f.pk)
+        self.assertEqual(f.s, "test2")
+

tests/regressiontests/model_fields/models.py

@@ -51 +51 @@
 class BigS(models.Model):
     s = models.SlugField(max_length=255)
 
+class FooGetSet(models.Model):
+    s = models.SlugField(max_length=255)
 
+    @s.getter
+    def get_s(self):
+        return self._s
+    @s.setter
+    def set_s(self, value):
+        if value is "not_acceptable":
+            raise ValueError("not acceptable")
+        self._s = value
+
 ###############################################################################
 # ImageField