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Fixed #12734. Deferred fields will now be properly converted to pytho…

…n when accessed. Thanks, Alex Gaynor.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12579 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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commit ff963358d7d3eb31b51f3d74581b8e17025e3859 1 parent 16fe73d
@jkocherhans jkocherhans authored
View
20 django/db/models/query_utils.py
@@ -183,11 +183,29 @@ def __get__(self, instance, owner):
Retrieves and caches the value from the datastore on the first lookup.
Returns the cached value.
"""
+ from django.db.models.fields import FieldDoesNotExist
+
assert instance is not None
cls = self.model_ref()
data = instance.__dict__
if data.get(self.field_name, self) is self:
- data[self.field_name] = cls._base_manager.filter(pk=instance.pk).values_list(self.field_name, flat=True).using(instance._state.db).get()
+ # self.field_name is the attname of the field, but only() takes the
+ # actual name, so we need to translate it here.
+ try:
+ cls._meta.get_field_by_name(self.field_name)
+ name = self.field_name
+ except FieldDoesNotExist:
+ name = [f.name for f in cls._meta.fields
+ if f.attname == self.field_name][0]
+ # We use only() instead of values() here because we want the
+ # various data coersion methods (to_python(), etc.) to be called
+ # here.
+ val = getattr(
+ cls._base_manager.filter(pk=instance.pk).only(name).using(
+ instance._state.db).get(),
+ self.field_name
+ )
+ data[self.field_name] = val
return data[self.field_name]
def __set__(self, instance, value):
View
71 tests/modeltests/field_subclassing/fields.py
@@ -0,0 +1,71 @@
+from django.core.exceptions import FieldError
+from django.db import models
+from django.utils import simplejson as json
+from django.utils.encoding import force_unicode
+
+
+class Small(object):
+ """
+ A simple class to show that non-trivial Python objects can be used as
+ attributes.
+ """
+ def __init__(self, first, second):
+ self.first, self.second = first, second
+
+ def __unicode__(self):
+ return u'%s%s' % (force_unicode(self.first), force_unicode(self.second))
+
+ def __str__(self):
+ return unicode(self).encode('utf-8')
+
+class SmallField(models.Field):
+ """
+ Turns the "Small" class into a Django field. Because of the similarities
+ with normal character fields and the fact that Small.__unicode__ does
+ something sensible, we don't need to implement a lot here.
+ """
+ __metaclass__ = models.SubfieldBase
+
+ def __init__(self, *args, **kwargs):
+ kwargs['max_length'] = 2
+ super(SmallField, self).__init__(*args, **kwargs)
+
+ def get_internal_type(self):
+ return 'CharField'
+
+ def to_python(self, value):
+ if isinstance(value, Small):
+ return value
+ return Small(value[0], value[1])
+
+ def get_db_prep_save(self, value):
+ return unicode(value)
+
+ def get_db_prep_lookup(self, lookup_type, value):
+ if lookup_type == 'exact':
+ return force_unicode(value)
+ if lookup_type == 'in':
+ return [force_unicode(v) for v in value]
+ if lookup_type == 'isnull':
+ return []
+ raise FieldError('Invalid lookup type: %r' % lookup_type)
+
+
+class JSONField(models.TextField):
+ __metaclass__ = models.SubfieldBase
+
+ description = ("JSONField automatically serializes and desializes values to "
+ "and from JSON.")
+
+ def to_python(self, value):
+ if not value:
+ return None
+
+ if isinstance(value, basestring):
+ value = json.loads(value)
+ return value
+
+ def get_db_prep_save(self, value):
+ if value is None:
+ return None
+ return json.dumps(value)
View
51 tests/modeltests/field_subclassing/models.py
@@ -2,56 +2,12 @@
Tests for field subclassing.
"""
+from django.core import serializers
from django.db import models
from django.utils.encoding import force_unicode
-from django.core import serializers
-from django.core.exceptions import FieldError
-
-class Small(object):
- """
- A simple class to show that non-trivial Python objects can be used as
- attributes.
- """
- def __init__(self, first, second):
- self.first, self.second = first, second
-
- def __unicode__(self):
- return u'%s%s' % (force_unicode(self.first), force_unicode(self.second))
-
- def __str__(self):
- return unicode(self).encode('utf-8')
-class SmallField(models.Field):
- """
- Turns the "Small" class into a Django field. Because of the similarities
- with normal character fields and the fact that Small.__unicode__ does
- something sensible, we don't need to implement a lot here.
- """
- __metaclass__ = models.SubfieldBase
+from fields import Small, SmallField, JSONField
- def __init__(self, *args, **kwargs):
- kwargs['max_length'] = 2
- super(SmallField, self).__init__(*args, **kwargs)
-
- def get_internal_type(self):
- return 'CharField'
-
- def to_python(self, value):
- if isinstance(value, Small):
- return value
- return Small(value[0], value[1])
-
- def get_db_prep_save(self, value):
- return unicode(value)
-
- def get_db_prep_lookup(self, lookup_type, value):
- if lookup_type == 'exact':
- return force_unicode(value)
- if lookup_type == 'in':
- return [force_unicode(v) for v in value]
- if lookup_type == 'isnull':
- return []
- raise FieldError('Invalid lookup type: %r' % lookup_type)
class MyModel(models.Model):
name = models.CharField(max_length=10)
@@ -60,6 +16,9 @@ class MyModel(models.Model):
def __unicode__(self):
return force_unicode(self.name)
+class DataModel(models.Model):
+ data = JSONField()
+
__test__ = {'API_TESTS': ur"""
# Creating a model with custom fields is done as per normal.
>>> s = Small(1, 2)
View
21 tests/modeltests/field_subclassing/tests.py
@@ -0,0 +1,21 @@
+from django.test import TestCase
+
+from models import DataModel
+
+
+class CustomField(TestCase):
+ def test_defer(self):
+ d = DataModel.objects.create(data=[1, 2, 3])
+
+ self.assertTrue(isinstance(d.data, list))
+
+ d = DataModel.objects.get(pk=d.pk)
+ self.assertTrue(isinstance(d.data, list))
+ self.assertEqual(d.data, [1, 2, 3])
+
+ d = DataModel.objects.defer("data").get(pk=d.pk)
+ d.save()
+
+ d = DataModel.objects.get(pk=d.pk)
+ self.assertTrue(isinstance(d.data, list))
+ self.assertEqual(d.data, [1, 2, 3])
View
3  tests/regressiontests/defer_regress/models.py
@@ -142,8 +142,7 @@ class ResolveThis(models.Model):
[<class 'regressiontests.defer_regress.models.Child'>, <class 'regressiontests.defer_regress.models.Item'>, <class 'regressiontests.defer_regress.models.Leaf'>, <class 'regressiontests.defer_regress.models.RelatedItem'>, <class 'regressiontests.defer_regress.models.ResolveThis'>]
>>> sorted(get_models(models.get_app('defer_regress'), include_deferred=True), key=lambda obj: obj._meta.object_name)
-[<class 'regressiontests.defer_regress.models.Child'>, <class 'regressiontests.defer_regress.models.Item'>, <class 'regressiontests.defer_regress.models.Item_Deferred_name'>, <class 'regressiontests.defer_regress.models.Item_Deferred_name_other_value_text'>, <class 'regressiontests.defer_regress.models.Item_Deferred_other_value_text_value'>, <class 'regressiontests.defer_regress.models.Item_Deferred_text_value'>, <class 'regressiontests.defer_regress.models.Leaf'>, <class 'regressiontests.defer_regress.models.Leaf_Deferred_name_value'>, <class 'regressiontests.defer_regress.models.Leaf_Deferred_second_child_value'>, <class 'regressiontests.defer_regress.models.Leaf_Deferred_value'>, <class 'regressiontests.defer_regress.models.RelatedItem'>, <class 'regressiontests.defer_regress.models.RelatedItem_Deferred_item_id'>, <class 'regressiontests.defer_regress.models.ResolveThis'>, <class 'regressiontests.defer_regress.models.ResolveThis_Deferred_num'>]
-
+[<class 'regressiontests.defer_regress.models.Child'>, <class 'regressiontests.defer_regress.models.Item'>, <class 'regressiontests.defer_regress.models.Item_Deferred_name'>, <class 'regressiontests.defer_regress.models.Item_Deferred_name_other_value_text'>, <class 'regressiontests.defer_regress.models.Item_Deferred_name_other_value_value'>, <class 'regressiontests.defer_regress.models.Item_Deferred_other_value_text_value'>, <class 'regressiontests.defer_regress.models.Item_Deferred_text_value'>, <class 'regressiontests.defer_regress.models.Leaf'>, <class 'regressiontests.defer_regress.models.Leaf_Deferred_child_id_second_child_id_value'>, <class 'regressiontests.defer_regress.models.Leaf_Deferred_name_value'>, <class 'regressiontests.defer_regress.models.Leaf_Deferred_second_child_value'>, <class 'regressiontests.defer_regress.models.Leaf_Deferred_value'>, <class 'regressiontests.defer_regress.models.RelatedItem'>, <class 'regressiontests.defer_regress.models.RelatedItem_Deferred_'>, <class 'regressiontests.defer_regress.models.RelatedItem_Deferred_item_id'>, <class 'regressiontests.defer_regress.models.ResolveThis'>, <class 'regressiontests.defer_regress.models.ResolveThis_Deferred_num'>]
"""
}
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