Django 3 / Python 3 support with some features

README.rst

@@ -122,6 +122,13 @@ Generally, ``SYNCHRO_REMOTE`` setting can behave in 3 different ways:
 
 __ synchro_on_remote_
 
+``SYNCHRO_CREATE_NEW`` setting
+--------------------------
+SYNCHRO_CREATE_NEW should contain list of classes that should not be updated on remote server instead if they are created
+on local database and the same primary key is taken on remote database, they will be created new instead of update.
+
+This feature is created keeping in mind the models that can not be changed but only created new
+ (i.e Logs)
 
 Remarks and features
 ====================

synchro/apps.py

@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 from django.apps import AppConfig
 
 
@@ -6,5 +7,5 @@ class SynchroConfig(AppConfig):
     verbose_name = 'Synchro'
 
     def ready(self):
-        from signals import synchro_connect
+        from .signals import synchro_connect
         synchro_connect()

synchro/core.py

@@ -1,3 +1,4 @@
-from utility import NaturalManager, reset_synchro
-from management.commands.synchronize import call_synchronize
-from signals import DisableSynchroLog, disable_synchro_log
+from __future__ import absolute_import
+from .utility import NaturalManager, reset_synchro
+from .management.commands.synchronize import call_synchronize
+from .signals import DisableSynchroLog, disable_synchro_log

synchro/handlers.py

@@ -1,6 +1,7 @@
-import settings
+from __future__ import absolute_import
+from . import settings
 settings.prepare()
-from models import ChangeLog, DeleteKey, ADDITION, CHANGE, DELETION, M2M_CHANGE
+from .models import ChangeLog, DeleteKey, ADDITION, CHANGE, DELETION, M2M_CHANGE
 
 
 def delete_redundant_change(cl):

synchro/management/commands/synchronize.py

@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 from datetime import datetime
 
 from django import VERSION
@@ -9,7 +10,8 @@
 
 from synchro.models import Reference, ChangeLog, DeleteKey, options as app_options
 from synchro.models import ADDITION, CHANGE, DELETION, M2M_CHANGE
-from synchro.settings import REMOTE, LOCAL
+from synchro.settings import REMOTE, LOCAL, SYNCHRO_CREATE_NEW
+import six
 
 
 if not hasattr(transaction, 'atomic'):
@@ -70,23 +72,46 @@ def save_with_fks(ct, obj, new_pk):
     """
     old_id = obj.pk
     obj._state.db = REMOTE
+    new_pk_list = SYNCHRO_CREATE_NEW  # Add models here that should not have the same primary key
+    rem = find_natural(ct, obj)
+    skip = False
+    if rem is not None:
+        if is_remote_newer(obj, rem):
+            skip = True
+
+    new_obj= obj.__class__.objects.filter(pk=obj.pk).using(REMOTE)
 
-    fks = (f for f in obj._meta.fields if f.rel)
-    for f in fks:
-        fk_id = f.value_from_object(obj)
-        if fk_id is not None:
-            fk_ct = ContentType.objects.get_for_model(f.rel.to)
-            rem, _ = ensure_exist(fk_ct, fk_id)
-            f.save_form_data(obj, rem)
+    if new_obj.exists() and type(obj) not in new_pk_list:
+        if not skip:
+            new_obj = new_obj[0]
+            values = obj.__dict__
+            values.pop('_state')
+            if '_django_cleanup_original_cache' in values.keys():
+                values.pop('_django_cleanup_original_cache')
+            obj.__class__.objects.filter(pk=obj.pk).using(REMOTE).update(**values)
+
+    else:
+        fks = (f for f in obj._meta.fields if (f.many_to_one or f.one_to_one))
+        for f in fks:
+            fk_id = f.value_from_object(obj)
+            if fk_id is not None:
+                fk_ct = ContentType.objects.get_for_model(f.related_model())
+                rem, _ = ensure_exist(fk_ct, fk_id)
+                f.save_form_data(obj, rem)
+
+        if not new_obj and type(obj) not in new_pk_list:
+            obj.pk = new_pk
+        else:
+            obj.pk = None
+        obj.save(using=REMOTE)
 
-    obj.pk = new_pk
-    obj.save(using=REMOTE)
     r, n = Reference.objects.get_or_create(content_type=ct, local_object_id=old_id,
                                            defaults={'remote_object_id': obj.pk})
     if not n and r.remote_object_id != obj.pk:
         r.remote_object_id = obj.pk
         r.save()
 
+
 M2M_CACHE = {}
 
 
@@ -120,7 +145,7 @@ def save_m2m(ct, obj, remote):
     _m2m = {}
 
     # handle m2m fields
-    for f, (to, through, me, he_id) in M2M_CACHE[model_name].iteritems():
+    for f, (to, through, me, he_id) in six.iteritems(M2M_CACHE[model_name]):
         fk_ct = ContentType.objects.get_for_model(to)
         out = []
         if through._meta.auto_created:
@@ -135,7 +160,7 @@ def save_m2m(ct, obj, remote):
                 out.append(inter)
         _m2m[f] = not through._meta.auto_created, out
 
-    for f, (intermediary, out) in _m2m.iteritems():
+    for f, (intermediary, out) in six.iteritems(_m2m):
         if not intermediary:
             setattr(remote, f, out)
         else:
@@ -187,7 +212,8 @@ def perform_add(ct, id, log=None):
             change_with_fks(ct, obj, rem)
             rem = obj
     else:
-        new_pk = None if obj._meta.has_auto_field else obj.pk
+        # new_pk = None if obj._meta.has_auto_field else obj.pk
+        new_pk = obj.pk
         create_with_fks(ct, obj, new_pk)
         rem = obj
     ref, _ = Reference.objects.get_or_create(content_type=ct, local_object_id=id,
@@ -261,8 +287,13 @@ def synchronize(self, *args, **options):
             raise exception_class('No REMOTE database specified in settings.')
 
         since = app_options.last_check
-        last_time = datetime.now()
-        logs = ChangeLog.objects.filter(date__gt=since).select_related().order_by('date', 'pk')
+        from django.utils import timezone
+
+        last_time = timezone.now()
+        check_time = last_time
+
+        filters = {"date__gt": since} if since else {}
+        logs = ChangeLog.objects.filter(**filters).select_related().order_by('date', 'pk')
 
         # Don't synchronize if object should be added/changed and later deleted;
         to_del = {}
@@ -281,7 +312,7 @@ def synchronize(self, *args, **options):
                 ACTIONS[log.action](log.content_type, log.object_id, log)
 
         if len(logs):
-            app_options.last_check = last_time
+            app_options.last_check = check_time
             return _t('Synchronization performed successfully.')
         else:
             return _t('No changes since last synchronization.')

synchro/migrations/0001_initial.py

@@ -0,0 +1,46 @@
+# Generated by Django 3.2.5 on 2022-06-20 11:58
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        ('contenttypes', '0002_remove_content_type_name'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='ChangeLog',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('object_id', models.CharField(max_length=256)),
+                ('date', models.DateTimeField(auto_now=True)),
+                ('action', models.PositiveSmallIntegerField(choices=[(1, 'Add'), (2, 'Change'), (3, 'Delete'), (4, 'M2m Change')])),
+                ('content_type', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='contenttypes.contenttype')),
+            ],
+        ),
+        migrations.CreateModel(
+            name='DeleteKey',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('key', models.CharField(max_length=256)),
+                ('changelog', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, to='synchro.changelog')),
+            ],
+        ),
+        migrations.CreateModel(
+            name='Reference',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('local_object_id', models.CharField(max_length=256)),
+                ('remote_object_id', models.CharField(max_length=256)),
+                ('content_type', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='contenttypes.contenttype')),
+            ],
+            options={
+                'unique_together': {('content_type', 'local_object_id')},
+            },
+        ),
+    ]

synchro/models.py

@@ -1,10 +1,12 @@
+from __future__ import absolute_import
 import django
 from django.contrib.admin.models import ADDITION, CHANGE, DELETION
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes.fields import GenericForeignKey
 from django.db import models
-from django.utils.timezone import now
+from django.utils import timezone
 import dbsettings
+import six
 
 
 M2M_CHANGE = 4
@@ -18,30 +20,30 @@
 
 
 class SynchroSettings(dbsettings.Group):
-    last_check = dbsettings.DateTimeValue('Last synchronization', default=now())
+    last_check = dbsettings.DateTimeValue('Last synchronization', default=timezone.now)
 options = SynchroSettings()
 
 
 class Reference(models.Model):
-    content_type = models.ForeignKey(ContentType)
-    local_object_id = models.CharField(max_length=20)
-    remote_object_id = models.CharField(max_length=20)
+    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
+    local_object_id = models.CharField(max_length=256)
+    remote_object_id = models.CharField(max_length=256)
 
     class Meta:
         unique_together = ('content_type', 'local_object_id')
 
 
 class ChangeLog(models.Model):
-    content_type = models.ForeignKey(ContentType)
-    object_id = models.CharField(max_length=20)
+    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
+    object_id = models.CharField(max_length=256)
     object = GenericForeignKey()
     date = models.DateTimeField(auto_now=True)
     action = models.PositiveSmallIntegerField(choices=ACTIONS)
 
     def __unicode__(self):
-        return u'ChangeLog for %s (%s)' % (unicode(self.object), self.get_action_display())
+        return u'ChangeLog for %s (%s)' % (six.text_type(self.object), self.get_action_display())
 
 
 class DeleteKey(models.Model):
-    changelog = models.OneToOneField(ChangeLog)
-    key = models.CharField(max_length=200)
+    changelog = models.OneToOneField(ChangeLog, on_delete=models.CASCADE)
+    key = models.CharField(max_length=256)

synchro/settings.py

@@ -1,6 +1,8 @@
+from __future__ import absolute_import
 from django.apps import apps
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
+from six.moves import map
 
 
 def get_all_models(app):
@@ -21,7 +23,7 @@ def parse(model):
             raise ImproperlyConfigured(
                 'SYNCHRO_MODELS: Model %s not found in %s app.' % (model, app))
         return m
-    return map(parse, l)
+    return list(map(parse, l))
 
 
 def parse_models(l):
@@ -66,6 +68,9 @@ def prepare():
 ALLOW_RESET = getattr(settings, 'SYNCHRO_ALLOW_RESET', True)
 DEBUG = getattr(settings, 'SYNCHRO_DEBUG', False)
 
+# list of classes that will be created new while sync i.e Logs class
+SYNCHRO_CREATE_NEW = getattr(settings, 'SYNCHRO_CREATE_NEW', [])
+
 if REMOTE is None:
     if not hasattr(settings, 'SYNCHRO_REMOTE'):
         import warnings

synchro/signals.py

@@ -1,10 +1,11 @@
+from __future__ import absolute_import
 from functools import wraps
 
 from django.db.models.signals import post_save, post_delete, m2m_changed
 
 
 def synchro_connect():
-    from handlers import save_changelog_add_chg, save_changelog_del, save_changelog_m2m
+    from .handlers import save_changelog_add_chg, save_changelog_del, save_changelog_m2m
     post_save.connect(save_changelog_add_chg, dispatch_uid='synchro_add_chg')
     post_delete.connect(save_changelog_del, dispatch_uid='synchro_del')
     m2m_changed.connect(save_changelog_m2m, dispatch_uid='synchro_m2m')

synchro/templates/synchro.html

@@ -18,11 +18,12 @@ <h1>{% trans "Synchronization" %}</h1>
 <form method="post">
     {% csrf_token %}
     <br>{% trans 'Last synchro time' %}: {{ last }}.
-    <br><br><input type="submit" name="synchro" value="{% trans 'Synchronize' %}">
+
+    <br><br><input type="submit" name="synchro" {% if not remote_db %}disabled{% endif %} value="{% trans 'Synchronize' %}">
 
     {% if reset_allowed %}
         <br><br><input type="submit" name="reset" value="{% trans 'Reset synchronization' %}"
-            onclick="return confirm('{% trans "All changes from last synchronization up to now will be forgotten and won't be synchronized in the future. Are you sure you want to proceed?" %}');">
+            onclick="return confirm(`All changes from last synchronization up to now will be forgotten and won't be synchronized in the future. Are you sure you want to proceed?`)">
     {% endif %}
 </form>
 </div>

synchro/test_urls.py

@@ -1,4 +1,5 @@
 # flake8: noqa
+from __future__ import absolute_import
 from django.contrib import admin
 from django.conf.urls import url, include
 

synchro/tests.py

@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import datetime
 
 from django import VERSION
@@ -16,10 +17,10 @@
 except ImportError:
     from django.utils.unittest.case import skipUnless
 
-from models import ChangeLog
-import settings as synchro_settings
-from signals import DisableSynchroLog, disable_synchro_log
-from utility import NaturalManager, reset_synchro, NaturalKeyModel
+from .models import ChangeLog
+from . import settings as synchro_settings
+from .signals import DisableSynchroLog, disable_synchro_log
+from .utility import NaturalManager, reset_synchro, NaturalKeyModel
 
 from django.contrib.auth import get_user_model
 User = get_user_model()
@@ -621,7 +622,7 @@ def test_foreign_keys(self):
         b = PkModelWithSkip.objects.db_manager(REMOTE).get(name='James')
         self.assertEqual(2, b.links.count())
         # Check if all submodels belong to remote db
-        self.assertTrue(all(map(lambda x: x._state.db == REMOTE, b.links.all())))
+        self.assertTrue(all([x._state.db == REMOTE for x in b.links.all()]))
 
     def test_disabling(self):
         """Test if logging can be disabled."""

synchro/urls.py

@@ -1,7 +1,8 @@
 # flake8: noqa
+from __future__ import absolute_import
 from django.conf.urls import url
 
-from views import synchro
+from .views import synchro
 
 
 urlpatterns = (