Bump version to 3.4

.pylintrc

@@ -1,6 +1,3 @@
-[MASTER]
-load-plugins=pylint_common, pylint_django
-
 [FORMAT]
 max-line-length=120
 

.scrutinizer.yml

@@ -0,0 +1,31 @@
+checks:
+    python:
+        code_rating: true
+        duplicate_code: true
+tools:
+    pylint:
+        python_version: '3'
+        config_file: .pylintrc
+filter:
+    excluded_paths:
+        - '*/tests/*'
+        - '*/migrations/*'
+build:
+    environment:
+        python: '3.5.0'
+        node: 'v6.2.0'
+        variables:
+            DJANGO_SETTINGS_MODULES: settings
+            DATABASE_URL: postgres://scrutinizer:scrutinizer@localhost:5434/localized_fields
+        postgresql: true
+        redis: true
+    dependencies:
+        override:
+            - 'pip install -r requirements/test.txt'
+    tests:
+        override:
+            -
+                command: coverage run manage.py test
+                coverage:
+                    file: '.coverage'
+                    format: 'py-cc'

README.rst

@@ -7,24 +7,14 @@ django-localized-fields
 .. image:: https://scrutinizer-ci.com/g/SectorLabs/django-localized-fields/badges/coverage.png
     :target: https://scrutinizer-ci.com/g/SectorLabs/django-localized-fields/
 
-.. image:: https://travis-ci.com/SectorLabs/django-localized-fields.svg?token=sFgxhDFpypxkMcvhRoSz&branch=master
-    :target: https://travis-ci.com/SectorLabs/django-localized-fields
+.. image:: https://img.shields.io/github/license/SectorLabs/django-localized-fields.svg
 
 .. image:: https://badge.fury.io/py/django-localized-fields.svg
     :target: https://pypi.python.org/pypi/django-localized-fields
 
-.. image:: https://img.shields.io/github/license/SectorLabs/django-localized-fields.svg
-
 ``django-localized-fields`` is an implementation of a field class for Django models that allows the field's value to be set in multiple languages. It does this by utilizing the ``hstore`` type (PostgreSQL specific), which is available as ``models.HStoreField`` in Django 1.10.
 
-This package requires Python 3.5 or newer and Django 1.10 or newer.
-
-In the pipeline
----------------
-We're working on making this easier to setup and use. Any feedback is apreciated. Here's a short list of things we're working to improve:
-
-* Make it unnecesarry to add anything to your `INSTALLED_APPS`.
-* Move generic PostgreSQL code to a separate package.
+This package requires Python 3.5 or newer, Django 1.10 or newer and PostgreSQL 9.6 or newer.
 
 Installation
 ------------
@@ -45,14 +35,14 @@ Installation
             'localized_fields'
         ]
 
-3. Set the database engine to ``localized_fields.db_backend``:
+3. Set the database engine to ``psqlextra.backend``:
 
     .. code-block:: python
 
         DATABASES = {
             'default': {
                 ...
-                'ENGINE': 'localized_fields.db_backend'
+                'ENGINE': 'psqlextra.backend'
             }
         }
 
@@ -257,34 +247,26 @@ Besides ``LocalizedField``, there's also:
 Frequently asked questions (FAQ)
 --------------------------------
 
-1. Why do I need to change the database back-end/engine?
-
-    We utilize PostgreSQL's `hstore` data type, which allows you to store key-value pairs in a column.  In order to create `UNIQUE` constraints on specific key, we need to create a special type of index. We could do this without a custom database back-end, but it would require everyone to manually write their migrations. By using a custom database back-end, we added support for this. When changing the `uniqueness` constraint on a `LocalizedField`, our custom database back-end takes care of creating, updating and deleting these constraints/indexes in the database.
-
-2. I am already using a custom database back-end, can I still use yours?
-
-    Yes. You can set the ``LOCALIZED_FIELDS_DB_BACKEND_BASE`` setting to your current back-end. This will instruct our custom database back-end to inherit from the database back-end you specified. **Warning**: this will only work if the base you specified indirectly inherits from the standard PostgreSQL database back-end.
-
-3. Does this package work with Python 2?
+1. Does this package work with Python 2?
 
     No. Only Python 3.5 or newer is supported. We're using type hints. These do not work well under older versions of Python.
 
-4. Does this package work with Django 1.X?
+2. Does this package work with Django 1.X?
 
     No. Only Django 1.10 or newer is supported. This is because we rely on Django's ``HStoreField``.
 
-5. Does this package come with support for Django Admin?
+3. Does this package come with support for Django Admin?
 
     Yes. Our custom fields come with a special form that will automatically be used in Django Admin if the field is of ``LocalizedField``.
 
-7. Why should I pick this over any of the other translation packages out there?
+4. Why should I pick this over any of the other translation packages out there?
 
     You should pick whatever you feel comfortable with. This package stores translations in your database without having to have translation tables. It however only works on PostgreSQL.
 
-8. I am using PostgreSQL <8.4, can I use this?
+5. I am using PostgreSQL <9.6, can I use this?
 
-    No. The ``hstore`` data type was introduced in PostgreSQL 8.4.
+    No. The ``hstore`` data type was introduced in PostgreSQL 9.6.
 
-9. I am using this package. Can I give you some beer?
+6. I am using this package. Can I give you some beer?
 
     Yes! If you're ever in the area of Cluj-Napoca, Romania, swing by :)

localized_fields/db_backend/base.py

@@ -1,224 +0,0 @@
-import importlib
-
-from django.conf import settings
-from django.core.exceptions import ImproperlyConfigured
-from django.db.backends.postgresql.base import \
-    DatabaseWrapper as Psycopg2DatabaseWrapper
-
-from ..fields import LocalizedField
-
-
-def _get_backend_base():
-    """Gets the base class for the custom database back-end.
-
-    This should be the Django PostgreSQL back-end. However,
-    some people are already using a custom back-end from
-    another package. We are nice people and expose an option
-    that allows them to configure the back-end we base upon.
-
-    As long as the specified base eventually also has
-    the PostgreSQL back-end as a base, then everything should
-    work as intended.
-    """
-    base_class_name = getattr(
-        settings,
-        'LOCALIZED_FIELDS_DB_BACKEND_BASE',
-        'django.db.backends.postgresql'
-    )
-
-    base_class_module = importlib.import_module(base_class_name + '.base')
-    base_class = getattr(base_class_module, 'DatabaseWrapper', None)
-
-    if not base_class:
-        raise ImproperlyConfigured((
-            '\'%s\' is not a valid database back-end.'
-            ' The module does not define a DatabaseWrapper class.'
-            ' Check the value of LOCALIZED_FIELDS_DB_BACKEND_BASE.'
-        ) % base_class_name)
-
-    if isinstance(base_class, Psycopg2DatabaseWrapper):
-        raise ImproperlyConfigured((
-            '\'%s\' is not a valid database back-end.'
-            ' It does inherit from the PostgreSQL back-end.'
-            ' Check the value of LOCALIZED_FIELDS_DB_BACKEND_BASE.'
-        ) % base_class_name)
-
-    return base_class
-
-
-def _get_schema_editor_base():
-    """Gets the base class for the schema editor.
-
-    We have to use the configured base back-end's
-    schema editor for this."""
-    return _get_backend_base().SchemaEditorClass
-
-
-class SchemaEditor(_get_schema_editor_base()):
-    """Custom schema editor for hstore indexes.
-
-    This allows us to put UNIQUE constraints for
-    localized fields."""
-
-    sql_hstore_unique_create = "CREATE UNIQUE INDEX {name} ON {table}{using} ({columns}){extra}"
-    sql_hstore_unique_drop = "DROP INDEX IF EXISTS {name}"
-
-    @staticmethod
-    def _hstore_unique_name(model, field, keys):
-        """Gets the name for a UNIQUE INDEX that applies
-        to one or more keys in a hstore field.
-
-        Arguments:
-            model:
-                The model the field is a part of.
-
-            field:
-                The hstore field to create a
-                UNIQUE INDEX for.
-
-            key:
-                The name of the hstore key
-                to create the name for.
-
-                This can also be a tuple
-                of multiple names.
-
-        Returns:
-            The name for the UNIQUE index.
-        """
-        postfix = '_'.join(keys)
-        return '{table_name}_{field_name}_unique_{postfix}'.format(
-            table_name=model._meta.db_table,
-            field_name=field.column,
-            postfix=postfix
-        )
-
-    def _drop_hstore_unique(self, model, field, keys):
-        """Drops a UNIQUE constraint for the specified hstore keys."""
-
-        name = self._hstore_unique_name(model, field, keys)
-        sql = self.sql_hstore_unique_drop.format(name=name)
-        self.execute(sql)
-
-    def _create_hstore_unique(self, model, field, keys):
-        """Creates a UNIQUE constraint for the specified hstore keys."""
-
-        name = self._hstore_unique_name(model, field, keys)
-        columns = [
-            '(%s->\'%s\')' % (field.column, key)
-            for key in keys
-        ]
-        sql = self.sql_hstore_unique_create.format(
-            name=name,
-            table=model._meta.db_table,
-            using='',
-            columns=','.join(columns),
-            extra=''
-        )
-        self.execute(sql)
-
-    def _apply_hstore_constraints(self, method, model, field):
-        """Creates/drops UNIQUE constraints for a field."""
-
-        def _compose_keys(constraint):
-            if isinstance(constraint, str):
-                return [constraint]
-
-            return constraint
-
-        uniqueness = getattr(field, 'uniqueness', None)
-        if not uniqueness:
-            return
-
-        for keys in uniqueness:
-            method(
-                model,
-                field,
-                _compose_keys(keys)
-            )
-
-    def _update_hstore_constraints(self, model, old_field, new_field):
-        """Updates the UNIQUE constraints for the specified field."""
-
-        old_uniqueness = getattr(old_field, 'uniqueness', None)
-        new_uniqueness = getattr(new_field, 'uniqueness', None)
-
-        # drop any old uniqueness constraints
-        if old_uniqueness:
-            self._apply_hstore_constraints(
-                self._drop_hstore_unique,
-                model,
-                old_field
-            )
-
-        # (re-)create uniqueness constraints
-        if new_uniqueness:
-            self._apply_hstore_constraints(
-                self._create_hstore_unique,
-                model,
-                new_field
-            )
-
-    def _alter_field(self, model, old_field, new_field, *args, **kwargs):
-        """Ran when the configuration on a field changed."""
-
-        super()._alter_field(
-            model, old_field, new_field,
-            *args, **kwargs
-        )
-
-        is_old_field_localized = isinstance(old_field, LocalizedField)
-        is_new_field_localized = isinstance(new_field, LocalizedField)
-
-        if is_old_field_localized or is_new_field_localized:
-            self._update_hstore_constraints(model, old_field, new_field)
-
-    def create_model(self, model):
-        """Ran when a new model is created."""
-
-        super().create_model(model)
-
-        for field in model._meta.local_fields:
-            if not isinstance(field, LocalizedField):
-                continue
-
-            self._apply_hstore_constraints(
-                self._create_hstore_unique,
-                model,
-                field
-            )
-
-    def delete_model(self, model):
-        """Ran when a model is being deleted."""
-
-        super().delete_model(model)
-
-        for field in model._meta.local_fields:
-            if not isinstance(field, LocalizedField):
-                continue
-
-            self._apply_hstore_constraints(
-                self._drop_hstore_unique,
-                model,
-                field
-            )
-
-
-class DatabaseWrapper(_get_backend_base()):
-    """Wraps the standard PostgreSQL database back-end.
-
-    Overrides the schema editor with our custom
-    schema editor and makes sure the `hstore`
-    extension is enabled."""
-
-    SchemaEditorClass = SchemaEditor
-
-    def prepare_database(self):
-        """Ran to prepare the configured database.
-
-        This is where we enable the `hstore` extension
-        if it wasn't enabled yet."""
-
-        super().prepare_database()
-        with self.cursor() as cursor:
-            cursor.execute('CREATE EXTENSION IF NOT EXISTS hstore')

localized_fields/fields/localized_field.py

@@ -1,8 +1,9 @@
 from django.conf import settings
-from django.contrib.postgres.fields import HStoreField
 from django.db.utils import IntegrityError
 
 from localized_fields import LocalizedFieldForm
+from psqlextra.fields import HStoreField
+
 from ..localized_value import LocalizedValue
 
 
@@ -14,13 +15,11 @@ class LocalizedField(HStoreField):
 
     Meta = None
 
-    def __init__(self, *args, uniqueness=None, **kwargs):
-        """Initializes a new instance of :see:LocalizedValue."""
+    def __init__(self, *args, **kwargs):
+        """Initializes a new instance of :see:LocalizedField."""
 
         super(LocalizedField, self).__init__(*args, **kwargs)
 
-        self.uniqueness = uniqueness
-
     @staticmethod
     def from_db_value(value, *_):
         """Turns the specified database value into its Python

localized_fields/fields/localized_uniqueslug_field.py

@@ -1,3 +1,5 @@
+from datetime import datetime
+
 from django.conf import settings
 from django.utils.text import slugify
 from django.core.exceptions import ImproperlyConfigured
@@ -7,8 +9,6 @@ from ..mixins import AtomicSlugRetryMixin
 from ..localized_value import LocalizedValue
 from .localized_autoslug_field import LocalizedAutoSlugField
 
-from datetime import datetime
-
 
 class LocalizedUniqueSlugField(LocalizedAutoSlugField):
     """Automatically provides slugs for a localized
@@ -30,14 +30,13 @@ class LocalizedUniqueSlugField(LocalizedAutoSlugField):
 
         kwargs['uniqueness'] = kwargs.pop('uniqueness', get_language_codes())
 
-        self.include_time = kwargs.pop('include_time', False)
-
         super(LocalizedUniqueSlugField, self).__init__(
             *args,
             **kwargs
         )
 
         self.populate_from = kwargs.pop('populate_from')
+        self.include_time = kwargs.pop('include_time', False)
 
     def deconstruct(self):
         """Deconstructs the field into something the database
@@ -85,11 +84,25 @@ class LocalizedUniqueSlugField(LocalizedAutoSlugField):
                 continue
 
             slug = slugify(value, allow_unicode=True)
+
+            # verify whether it's needed to re-generate a slug,
+            # if not, re-use the same slug
+            if instance.pk is not None:
+                current_slug = getattr(instance, self.name).get(lang_code)
+                if current_slug is not None:
+                    stripped_slug = current_slug[0:current_slug.rfind('-')]
+                    if slug == stripped_slug:
+                        slugs.set(lang_code, current_slug)
+                        continue
+
             if self.include_time:
                 slug += '-%d' % datetime.now().microsecond
 
             if instance.retries > 0:
-                slug += '-%d' % instance.retries
+                # do not add another - if we already added time
+                if not self.include_time:
+                    slug += '-'
+                slug += '%d' % instance.retries
 
             slugs.set(lang_code, slug)
 

localized_fields/models.py

@@ -1,12 +1,10 @@
-from django.db import models, transaction
-from django.db.utils import IntegrityError
-from django.conf import settings
+from psqlextra.models import PostgresModel
 
 from .fields import LocalizedField
 from .localized_value import LocalizedValue
 
 
-class LocalizedModel(models.Model):
+class LocalizedModel(PostgresModel):
     """A model that contains localized fields."""
 
     class Meta:

requirements/base.txt

@@ -0,0 +1 @@
+django-postgres-extra==1.4

requirements/test.txt

@@ -1,3 +1,5 @@
+-r base.txt
+
 coverage==4.2
 Django==1.10.2
 django-autoslug==1.9.3

settings.py

@@ -11,7 +11,7 @@ DATABASES = {
     'default': dj_database_url.config(default='postgres:///localized_fields')
 }
 
-DATABASES['default']['ENGINE'] = 'localized_fields.db_backend'
+DATABASES['default']['ENGINE'] = 'psqlextra.backend'
 
 LANGUAGE_CODE = 'en'
 LANGUAGES = (

setup.py

@@ -7,7 +7,7 @@ with open(os.path.join(os.path.dirname(__file__), 'README.rst')) as readme:
 
 setup(
     name='django-localized-fields',
-    version='2.9',
+    version='3.4',
     packages=find_packages(),
     include_package_data=True,
     license='MIT License',
@@ -17,6 +17,9 @@ setup(
     author='Sector Labs',
     author_email='open-source@sectorlabs.ro',
     keywords=['django', 'localized', 'language', 'models', 'fields'],
+    install_requires=[
+        'django-postgres-extra>=1.4'
+    ],
     classifiers=[
         'Environment :: Web Environment',
         'Framework :: Django',

tests/test_db_backend.py

@@ -1,87 +0,0 @@
-from unittest import mock
-
-from django.db import connection
-from django.apps import apps
-from django.conf import settings
-from django.test import TestCase
-from django.db.backends.base.schema import BaseDatabaseSchemaEditor
-
-from localized_fields import LocalizedField, get_language_codes
-
-from .fake_model import define_fake_model
-
-
-class DBBackendTestCase(TestCase):
-    """Tests the custom database back-end."""
-
-    @staticmethod
-    def test_hstore_extension_enabled():
-        """Tests whether the `hstore` extension was
-        enabled automatically."""
-
-        with connection.cursor() as cursor:
-            cursor.execute((
-                'SELECT count(*) FROM pg_extension '
-                'WHERE extname = \'hstore\''
-            ))
-
-            assert cursor.fetchone()[0] == 1
-
-    @classmethod
-    def test_migration_create_drop_model(cls):
-        """Tests whether models containing a :see:LocalizedField
-        with a `uniqueness` constraint get created properly,
-        with the contraints in the database."""
-
-        model = define_fake_model('NewModel', {
-            'title': LocalizedField(uniqueness=get_language_codes())
-        })
-
-        # create the model in db and verify the indexes are being created
-        with mock.patch.object(BaseDatabaseSchemaEditor, 'execute') as execute:
-            with connection.schema_editor() as schema_editor:
-                schema_editor.create_model(model)
-
-            create_index_calls = [
-                call for call in execute.mock_calls if 'CREATE UNIQUE INDEX' in str(call)
-            ]
-
-            assert len(create_index_calls) == len(settings.LANGUAGES)
-
-        # delete the model in the db and verify the indexes are being deleted
-        with mock.patch.object(BaseDatabaseSchemaEditor, 'execute') as execute:
-            with connection.schema_editor() as schema_editor:
-                schema_editor.delete_model(model)
-
-            drop_index_calls = [
-                call for call in execute.mock_calls if 'DROP INDEX' in str(call)
-            ]
-
-            assert len(drop_index_calls) == len(settings.LANGUAGES)
-
-    @classmethod
-    def test_migration_alter_field(cls):
-        """Tests whether the back-end correctly removes and
-        adds `uniqueness` constraints when altering a :see:LocalizedField."""
-
-        define_fake_model('ExistingModel', {
-            'title': LocalizedField(uniqueness=get_language_codes())
-        })
-
-        app_config = apps.get_app_config('tests')
-
-        with mock.patch.object(BaseDatabaseSchemaEditor, 'execute') as execute:
-            with connection.schema_editor() as schema_editor:
-                dynmodel = app_config.get_model('ExistingModel')
-                schema_editor.alter_field(
-                    dynmodel,
-                    dynmodel._meta.fields[1],
-                    dynmodel._meta.fields[1]
-                )
-
-            index_calls = [
-                call for call in execute.mock_calls
-                if 'INDEX' in str(call) and 'title' in str(call)
-            ]
-
-            assert len(index_calls) == len(settings.LANGUAGES) * 2

tests/test_localized_slug_fields.py

@@ -1,11 +1,12 @@
+import copy
+
 from django import forms
 from django.conf import settings
 from django.test import TestCase
 from django.db.utils import IntegrityError
-from django.utils.text import slugify
-
 from localized_fields import (LocalizedField, LocalizedAutoSlugField,
                               LocalizedUniqueSlugField)
+from django.utils.text import slugify
 
 from .fake_model import get_fake_model
 
@@ -83,6 +84,33 @@ class LocalizedSlugFieldTestCase(TestCase):
 
         assert obj.slug.en.startswith('%s-' % title)
 
+    @classmethod
+    def test_uniue_slug_no_change(cls):
+        """Tests whether slugs are not re-generated if not needed."""
+
+        NoChangeSlugModel = get_fake_model(
+            'NoChangeSlugModel',
+            {
+                'title': LocalizedField(),
+                'slug': LocalizedUniqueSlugField(populate_from='title', include_time=True)
+            }
+        )
+
+        title = 'myuniquetitle'
+
+        obj = NoChangeSlugModel()
+        obj.title.en = title
+        obj.title.nl = title
+        obj.save()
+
+        old_slug_en = copy.deepcopy(obj.slug.en)
+        old_slug_nl = copy.deepcopy(obj.slug.nl)
+        obj.title.nl += 'beer'
+        obj.save()
+
+        assert old_slug_en == obj.slug.en
+        assert old_slug_nl != obj.slug.nl
+
     def test_unique_slug_unique_max_retries(self):
         """Tests whether the unique slug implementation doesn't
         try to find a slug forever and gives up after a while."""