Commit 55bcc8ac authored by Joseph Kocherhans's avatar Joseph Kocherhans
Browse files

[1.1.X] Fixed #12734. Deferred fields will now be properly converted to python... 

[1.1.X] Fixed #12734. Deferred fields will now be properly converted to python when accessed. Backport of r12579 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@12692 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent daec7345

django/db/models/query_utils.py

+18 −1
Original line number Diff line number Diff line
@@ -182,11 +182,28 @@ class DeferredAttribute(object): 
        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).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).get(),

                self.field_name

            )

            data[self.field_name] = val

        return data[self.field_name]



    def __set__(self, instance, value):

tests/modeltests/field_subclassing/fields.py

0 → 100644
+71 −0
Original line number Diff line number Diff line 
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)

tests/modeltests/field_subclassing/models.py

+5 −46
Original line number Diff line number Diff line
@@ -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))

from fields import Small, SmallField, JSONField



    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 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)

tests/modeltests/field_subclassing/tests.py

0 → 100644
+21 −0
Original line number Diff line number Diff line 
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])

tests/regressiontests/defer_regress/models.py

+2 −3
Original line number Diff line number Diff line
@@ -142,9 +142,8 @@ False 
>>> sorted(get_models(models.get_app('defer_regress')), key=lambda obj: obj.__class__.__name__)

[<class 'regressiontests.defer_regress.models.Item'>, <class 'regressiontests.defer_regress.models.RelatedItem'>, <class 'regressiontests.defer_regress.models.Child'>, <class 'regressiontests.defer_regress.models.Leaf'>]



>>> sorted(get_models(models.get_app('defer_regress'), include_deferred=True), key=lambda obj: obj.__class__.__name__)

[<class 'regressiontests.defer_regress.models.Item'>, <class 'regressiontests.defer_regress.models.RelatedItem'>, <class 'regressiontests.defer_regress.models.Child'>, <class 'regressiontests.defer_regress.models.Leaf'>, <class 'regressiontests.defer_regress.models.Item_Deferred_text_value'>, <class 'regressiontests.defer_regress.models.Item_Deferred_name_other_value_text'>, <class 'regressiontests.defer_regress.models.RelatedItem_Deferred_item_id'>, <class 'regressiontests.defer_regress.models.Leaf_Deferred_second_child_value'>, <class 'regressiontests.defer_regress.models.Leaf_Deferred_name_value'>, <class 'regressiontests.defer_regress.models.Item_Deferred_name'>, <class 'regressiontests.defer_regress.models.Item_Deferred_other_value_text_value'>, <class 'regressiontests.defer_regress.models.Leaf_Deferred_value'>]



>>> 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_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'>]

"""

}