no need inheritance from LocalizedModel anymore. Introduction of LocalizedValueDescriptor

README.rst

@@ -62,15 +62,14 @@ Usage
 
 Preparation
 ^^^^^^^^^^^
-Inherit your model from ``LocalizedModel`` and declare fields on your model as ``LocalizedField``:
+Declare fields on your model as ``LocalizedField``:
 
 .. code-block:: python
 
-     from localized_fields.models import LocalizedModel
      from localized_fields.fields import LocalizedField
 
 
-     class MyModel(LocalizedModel):
+     class MyModel(models.Model):
          title = LocalizedField()
 
 ``django-localized-fields`` integrates with Django's i18n system, in order for certain languages to be available you have to correctly configure the ``LANGUAGES`` and ``LANGUAGE_CODE`` settings:
@@ -136,14 +135,14 @@ At the moment, it is not possible to select two languages to be marked as requir
 
     .. code-block:: python
 
-        class MyModel(LocalizedModel):
+        class MyModel(models.Model):
             title = LocalizedField(required=True)
 
 * Make all languages optional:
 
     .. code-block:: python
 
-        class MyModel(LocalizedModel):
+        class MyModel(models.Model):
             title = LocalizedField(null=True)
 
 **Uniqueness**
@@ -154,7 +153,7 @@ By default the values stored in a ``LocalizedField`` are *not unique*. You can e
 
     .. code-block:: python
 
-        class MyModel(LocalizedModel):
+        class MyModel(models.Model):
             title = LocalizedField(uniqueness=['en', 'ro'])
 
 * Enforce uniqueness for **all** languages:
@@ -163,14 +162,14 @@ By default the values stored in a ``LocalizedField`` are *not unique*. You can e
 
         from localized_fields import get_language_codes
 
-        class MyModel(LocalizedModel):
+        class MyModel(models.Model):
             title = LocalizedField(uniqueness=get_language_codes())
 
 * Enforce uniqueness for one ore more languages **together** (similar to Django's ``unique_together``):
 
     .. code-block:: python
 
-        class MyModel(LocalizedModel):
+        class MyModel(models.Model):
             title = LocalizedField(uniqueness=[('en', 'ro')])
 
 * Enforce uniqueness for **all** languages **together**:
@@ -179,7 +178,7 @@ By default the values stored in a ``LocalizedField`` are *not unique*. You can e
 
         from localized_fields import get_language_codes
 
-        class MyModel(LocalizedModel):
+        class MyModel(models.Model):
             title = LocalizedField(uniqueness=[(*get_language_codes())])
 
 
@@ -193,12 +192,11 @@ Besides ``LocalizedField``, there's also:
 
           .. code-block:: python
 
-              from localized_fields import (LocalizedModel,
+              from localized_fields import (AtomicSlugRetryMixin,
-                                            AtomicSlugRetryMixin,
                                             LocalizedField,
                                             LocalizedUniqueSlugField)
 
-              class MyModel(AtomicSlugRetryMixin, LocalizedModel):
+              class MyModel(AtomicSlugRetryMixin, models.Model):
                    title = LocalizedField()
                    slug = LocalizedUniqueSlugField(populate_from='title')
 
@@ -218,11 +216,10 @@ Besides ``LocalizedField``, there's also:
 
           .. code-block:: python
 
-              from localized_fields import (LocalizedModel,
+              from localized_fields import (LocalizedField,
-                                            LocalizedField,
                                             LocalizedUniqueSlugField)
 
-              class MyModel(LocalizedModel):
+              class MyModel(models.Model):
                    title = LocalizedField()
                    slug = LocalizedAutoSlugField(populate_from='title')
 
@@ -236,11 +233,10 @@ Besides ``LocalizedField``, there's also:
 
            .. code-block:: python
 
-              from localized_fields import (LocalizedModel,
+              from localized_fields import (LocalizedField,
-                                            LocalizedField,
                                             LocalizedBleachField)
 
-              class MyModel(LocalizedModel):
+              class MyModel(models.Model):
                    title = LocalizedField()
                    description = LocalizedBleachField()
 

localized_fields/__init__.py

@@ -3,7 +3,6 @@ from .forms import LocalizedFieldForm, LocalizedFieldWidget
 from .fields import (LocalizedField, LocalizedBleachField,
                      LocalizedAutoSlugField, LocalizedUniqueSlugField)
 from .mixins import AtomicSlugRetryMixin
-from .models import LocalizedModel
 from .localized_value import LocalizedValue
 
 __all__ = [
@@ -15,6 +14,5 @@ __all__ = [
     'LocalizedBleachField',
     'LocalizedFieldWidget',
     'LocalizedFieldForm',
-    'LocalizedModel',
     'AtomicSlugRetryMixin'
 ]

localized_fields/fields/localized_field.py

@@ -1,5 +1,6 @@
 from django.conf import settings
 from django.db.utils import IntegrityError
+from django.utils import six, translation
 
 from localized_fields import LocalizedFieldForm
 from psqlextra.fields import HStoreField
@@ -7,6 +8,63 @@ from psqlextra.fields import HStoreField
 from ..localized_value import LocalizedValue
 
 
+class LocalizedValueDescriptor(object):
+    """
+    The descriptor for the localized value attribute on the model instance.
+    Returns a :see:LocalizedValue when accessed so you can do stuff like::
+
+        >>> from myapp.models import MyModel
+        >>> instance = MyModel()
+        >>> instance.value.en = 'English value'
+
+    Assigns a strings to active language key in :see:LocalizedValue on
+    assignment so you can do::
+
+        >>> from django.utils import translation
+        >>> from myapp.models import MyModel
+
+        >>> translation.activate('nl')
+        >>> instance = MyModel()
+        >>> instance.title = 'dutch title'
+        >>> print(instance.title.nl) # prints 'dutch title'
+    """
+    def __init__(self, field):
+        self.field = field
+
+    def __get__(self, instance, cls=None):
+        if instance is None:
+            return self
+
+        # This is slightly complicated, so worth an explanation.
+        # `instance.localizedvalue` needs to ultimately return some instance of
+        # `LocalizedValue`, probably a subclass.
+
+        # The instance dict contains whatever was originally assigned
+        # in __set__.
+        if self.field.name in instance.__dict__:
+            value = instance.__dict__[self.field.name]
+        else:
+            instance.refresh_from_db(fields=[self.field.name])
+            value = getattr(instance, self.field.name)
+
+        if value is None:
+            attr = self.field.attr_class()
+            instance.__dict__[self.field.name] = attr
+
+        if isinstance(value, dict):
+            attr = self.field.attr_class(value)
+            instance.__dict__[self.field.name] = attr
+
+        return instance.__dict__[self.field.name]
+
+    def __set__(self, instance, value):
+        if isinstance(value, six.string_types):
+            self.__get__(instance).set(translation.get_language() or
+                                       settings.LANGUAGE_CODE, value)
+        else:
+            instance.__dict__[self.field.name] = value
+
+
 class LocalizedField(HStoreField):
     """A field that has the same value in multiple languages.
 
@@ -15,13 +73,23 @@ class LocalizedField(HStoreField):
 
     Meta = None
 
+    # The class to wrap instance attributes in. Accessing to field attribute in
+    # model instance will always return an instance of attr_class.
+    attr_class = LocalizedValue
+
+    # The descriptor to use for accessing the attribute off of the class.
+    descriptor_class = LocalizedValueDescriptor
+
     def __init__(self, *args, **kwargs):
         """Initializes a new instance of :see:LocalizedField."""
 
         super(LocalizedField, self).__init__(*args, **kwargs)
 
-    @staticmethod
+    def contribute_to_class(self, cls, name, **kwargs):
-    def from_db_value(value, *_):
+        super(LocalizedField, self).contribute_to_class(cls, name, **kwargs)
+        setattr(cls, self.name, self.descriptor_class(self))
+
+    def from_db_value(self, value, *_):
         """Turns the specified database value into its Python
         equivalent.
 
@@ -36,9 +104,9 @@ class LocalizedField(HStoreField):
         """
 
         if not value:
-            return LocalizedValue()
+            return self.attr_class()
 
-        return LocalizedValue(value)
+        return self.attr_class(value)
 
     def to_python(self, value: dict) -> LocalizedValue:
         """Turns the specified database value into its Python
@@ -55,9 +123,9 @@ class LocalizedField(HStoreField):
         """
 
         if not value or not isinstance(value, dict):
-            return LocalizedValue()
+            return self.attr_class()
 
-        return LocalizedValue(value)
+        return self.attr_class(value)
 
     def get_prep_value(self, value: LocalizedValue) -> dict:
         """Turns the specified value into something the database

localized_fields/models.py

@@ -1,34 +1 @@
-from psqlextra.models import PostgresModel
 
-from .fields import LocalizedField
-from .localized_value import LocalizedValue
-
-
-class LocalizedModel(PostgresModel):
-    """A model that contains localized fields."""
-
-    class Meta:
-        abstract = True
-
-    def __init__(self, *args, **kwargs):
-        """Initializes a new instance of :see:LocalizedModel.
-
-        Here we set all the fields that are of :see:LocalizedField
-        to an instance of :see:LocalizedValue in case they are none
-        so that the user doesn't explicitely have to do so."""
-
-        super(LocalizedModel, self).__init__(*args, **kwargs)
-
-        for field in self._meta.get_fields():
-            if not isinstance(field, LocalizedField):
-                continue
-
-            value = getattr(self, field.name, None)
-
-            if not isinstance(value, LocalizedValue):
-                if isinstance(value, dict):
-                    value = LocalizedValue(value)
-                else:
-                    value = LocalizedValue()
-
-            setattr(self, field.name, value)

tests/fake_model.py

@@ -1,8 +1,9 @@
 from django.db import connection, migrations
+from django.db import models
 from django.db.migrations.executor import MigrationExecutor
 from django.contrib.postgres.operations import HStoreExtension
 
-from localized_fields import LocalizedModel, AtomicSlugRetryMixin
+from localized_fields import AtomicSlugRetryMixin
 
 
 def define_fake_model(name='TestModel', fields=None):
@@ -14,7 +15,7 @@ def define_fake_model(name='TestModel', fields=None):
 
     if fields:
         attributes.update(fields)
-    model = type(name, (AtomicSlugRetryMixin,LocalizedModel,), attributes)
+    model = type(name, (AtomicSlugRetryMixin, models.Model), attributes)
 
     return model
 

tests/test_localized_field.py

@@ -172,7 +172,7 @@ class LocalizedFieldTestCase(TestCase):
         produces the expected :see:LocalizedValue."""
 
         input_data = get_init_values()
-        localized_value = LocalizedField.from_db_value(input_data)
+        localized_value = LocalizedField().from_db_value(input_data)
 
         for lang_code, _ in settings.LANGUAGES:
             assert getattr(localized_value, lang_code) == input_data[lang_code]
@@ -182,7 +182,7 @@ class LocalizedFieldTestCase(TestCase):
         """Tests whether the :see:from_db_valuei function
         correctly handles None values."""
 
-        localized_value = LocalizedField.from_db_value(None)
+        localized_value = LocalizedField().from_db_value(None)
 
         for lang_code, _ in settings.LANGUAGES:
             assert localized_value.get(lang_code) is None