Remove common app's Singleton model and use django-solo's SingletonModel instead

mayan/apps/acls/forms.py

@@ -51,8 +51,8 @@ class BaseHolderSelectionForm(forms.Form):
 
 
 class HolderSelectionForm(BaseHolderSelectionForm):
-    special_holders = [AnonymousUserSingleton.objects.get()]
+    special_holders = [AnonymousUserSingleton.objects.get_or_create()[0]]
 
 
 class ClassHolderSelectionForm(BaseHolderSelectionForm):
-    special_holders = [AnonymousUserSingleton.objects.get(), CreatorSingleton.objects.get()]
+    special_holders = [AnonymousUserSingleton.objects.get_or_create()[0], CreatorSingleton.objects.get_or_create()[0]]

mayan/apps/acls/migrations/0001_initial.py

@@ -0,0 +1,89 @@
+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Adding model 'AccessEntry'
+        db.create_table(u'acls_accessentry', (
+            (u'id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('permission', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['permissions.StoredPermission'])),
+            ('holder_type', self.gf('django.db.models.fields.related.ForeignKey')(related_name='access_holder', to=orm['contenttypes.ContentType'])),
+            ('holder_id', self.gf('django.db.models.fields.PositiveIntegerField')()),
+            ('content_type', self.gf('django.db.models.fields.related.ForeignKey')(related_name='object_content_type', to=orm['contenttypes.ContentType'])),
+            ('object_id', self.gf('django.db.models.fields.PositiveIntegerField')()),
+        ))
+        db.send_create_signal(u'acls', ['AccessEntry'])
+
+        # Adding model 'DefaultAccessEntry'
+        db.create_table(u'acls_defaultaccessentry', (
+            (u'id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('permission', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['permissions.StoredPermission'])),
+            ('holder_type', self.gf('django.db.models.fields.related.ForeignKey')(related_name='default_access_entry_holder', to=orm['contenttypes.ContentType'])),
+            ('holder_id', self.gf('django.db.models.fields.PositiveIntegerField')()),
+            ('content_type', self.gf('django.db.models.fields.related.ForeignKey')(related_name='default_access_entry_class', to=orm['contenttypes.ContentType'])),
+        ))
+        db.send_create_signal(u'acls', ['DefaultAccessEntry'])
+
+        # Adding model 'CreatorSingleton'
+        db.create_table(u'acls_creatorsingleton', (
+            (u'id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('lock_id', self.gf('django.db.models.fields.CharField')(default='1', unique=True, max_length=1)),
+        ))
+        db.send_create_signal(u'acls', ['CreatorSingleton'])
+
+
+    def backwards(self, orm):
+        # Deleting model 'AccessEntry'
+        db.delete_table(u'acls_accessentry')
+
+        # Deleting model 'DefaultAccessEntry'
+        db.delete_table(u'acls_defaultaccessentry')
+
+        # Deleting model 'CreatorSingleton'
+        db.delete_table(u'acls_creatorsingleton')
+
+
+    models = {
+        u'acls.accessentry': {
+            'Meta': {'object_name': 'AccessEntry'},
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'object_content_type'", 'to': u"orm['contenttypes.ContentType']"}),
+            'holder_id': ('django.db.models.fields.PositiveIntegerField', [], {}),
+            'holder_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'access_holder'", 'to': u"orm['contenttypes.ContentType']"}),
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'object_id': ('django.db.models.fields.PositiveIntegerField', [], {}),
+            'permission': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['permissions.StoredPermission']"})
+        },
+        u'acls.creatorsingleton': {
+            'Meta': {'object_name': 'CreatorSingleton'},
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'lock_id': ('django.db.models.fields.CharField', [], {'default': "'1'", 'unique': 'True', 'max_length': '1'})
+        },
+        u'acls.defaultaccessentry': {
+            'Meta': {'object_name': 'DefaultAccessEntry'},
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'default_access_entry_class'", 'to': u"orm['contenttypes.ContentType']"}),
+            'holder_id': ('django.db.models.fields.PositiveIntegerField', [], {}),
+            'holder_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'default_access_entry_holder'", 'to': u"orm['contenttypes.ContentType']"}),
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'permission': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['permissions.StoredPermission']"})
+        },
+        u'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        u'permissions.storedpermission': {
+            'Meta': {'ordering': "('namespace',)", 'unique_together': "(('namespace', 'name'),)", 'object_name': 'StoredPermission'},
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '64'}),
+            'namespace': ('django.db.models.fields.CharField', [], {'max_length': '64'})
+        }
+    }
+
+    complete_apps = ['acls']

mayan/apps/acls/migrations/0002_auto__del_field_creatorsingleton_lock_id.py

@@ -0,0 +1,59 @@
+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Deleting field 'CreatorSingleton.lock_id'
+        db.delete_column(u'acls_creatorsingleton', 'lock_id')
+
+
+    def backwards(self, orm):
+        # Adding field 'CreatorSingleton.lock_id'
+        db.add_column(u'acls_creatorsingleton', 'lock_id',
+                      self.gf('django.db.models.fields.CharField')(default='1', max_length=1, unique=True),
+                      keep_default=False)
+
+
+    models = {
+        u'acls.accessentry': {
+            'Meta': {'object_name': 'AccessEntry'},
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'object_content_type'", 'to': u"orm['contenttypes.ContentType']"}),
+            'holder_id': ('django.db.models.fields.PositiveIntegerField', [], {}),
+            'holder_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'access_holder'", 'to': u"orm['contenttypes.ContentType']"}),
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'object_id': ('django.db.models.fields.PositiveIntegerField', [], {}),
+            'permission': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['permissions.StoredPermission']"})
+        },
+        u'acls.creatorsingleton': {
+            'Meta': {'object_name': 'CreatorSingleton'},
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'})
+        },
+        u'acls.defaultaccessentry': {
+            'Meta': {'object_name': 'DefaultAccessEntry'},
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'default_access_entry_class'", 'to': u"orm['contenttypes.ContentType']"}),
+            'holder_id': ('django.db.models.fields.PositiveIntegerField', [], {}),
+            'holder_type': ('django.db.models.fields.related.ForeignKey', [], {'related_name': "'default_access_entry_holder'", 'to': u"orm['contenttypes.ContentType']"}),
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'permission': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['permissions.StoredPermission']"})
+        },
+        u'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        u'permissions.storedpermission': {
+            'Meta': {'ordering': "('namespace',)", 'unique_together': "(('namespace', 'name'),)", 'object_name': 'StoredPermission'},
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '64'}),
+            'namespace': ('django.db.models.fields.CharField', [], {'max_length': '64'})
+        }
+    }
+
+    complete_apps = ['acls']

mayan/apps/acls/models.py

@@ -8,8 +8,9 @@ from django.utils.translation import ugettext
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.contenttypes import generic
 
+from solo.models import SingletonModel
+
 from permissions.models import StoredPermission
-from common.models import Singleton, SingletonManager
 
 from .managers import AccessEntryManager, DefaultAccessEntryManager
 from .classes import AccessObjectClass
@@ -92,7 +93,7 @@ class DefaultAccessEntry(models.Model):
         return u'%s: %s' % (self.content_type, self.content_object)
 
 
-class CreatorSingletonManager(SingletonManager):
+class CreatorSingletonManager(models.Manager):
     def passthru_check(self, holder, creator=None):
         if isinstance(holder, self.model):
             # TODO: raise explicit error if is instance and creator=None
@@ -101,7 +102,7 @@ class CreatorSingletonManager(SingletonManager):
             return holder
 
 
-class CreatorSingleton(Singleton):
+class CreatorSingleton(SingletonModel):
     objects = CreatorSingletonManager()
 
     def __unicode__(self):

mayan/apps/common/__init__.py

@@ -17,7 +17,7 @@ from navigation.api import register_links, register_top_menu
 from .conf import settings as common_settings
 from .conf.settings import (AUTO_CREATE_ADMIN, AUTO_ADMIN_USERNAME,
     AUTO_ADMIN_PASSWORD, TEMPORARY_DIRECTORY)
-from .models import AutoAdminSingleton
+from .models import AnonymousUserSingleton, AutoAdminSingleton
 from .utils import validate_path
 
 
@@ -61,7 +61,7 @@ def create_superuser(sender, **kwargs):
             assert auth_models.User.objects.create_superuser(AUTO_ADMIN_USERNAME, 'autoadmin@autoadmin.com', AUTO_ADMIN_PASSWORD)
             admin = auth_models.User.objects.get(username=AUTO_ADMIN_USERNAME)
             # Store the auto admin password properties to display the first login message
-            auto_admin_properties = AutoAdminSingleton.objects.get()
+            auto_admin_properties, created = AutoAdminSingleton.objects.get_or_create()
             auto_admin_properties.account = admin
             auto_admin_properties.password = AUTO_ADMIN_PASSWORD
             auto_admin_properties.password_hash = admin.password
@@ -74,7 +74,7 @@ def create_superuser(sender, **kwargs):
 def auto_admin_account_passwd_change(sender, instance, **kwargs):
     try:
         with transaction.atomic():
-            auto_admin_properties = AutoAdminSingleton.objects.get()
+            auto_admin_properties, created = AutoAdminSingleton.objects.get_or_create()
             if instance == auto_admin_properties.account and instance.password != auto_admin_properties.password_hash:
                 # Only delete the auto admin properties when the password has been changed
                 auto_admin_properties.delete(force=True)

mayan/apps/common/migrations/0005_auto__del_field_autoadminsingleton_lock_id__del_field_anonymoususersin.py

@@ -0,0 +1,80 @@
+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Deleting field 'AutoAdminSingleton.lock_id'
+        db.delete_column(u'common_autoadminsingleton', 'lock_id')
+
+        # Deleting field 'AnonymousUserSingleton.lock_id'
+        db.delete_column(u'common_anonymoususersingleton', 'lock_id')
+
+
+    def backwards(self, orm):
+        # Adding field 'AutoAdminSingleton.lock_id'
+        db.add_column(u'common_autoadminsingleton', 'lock_id',
+                      self.gf('django.db.models.fields.CharField')(default=1, max_length=1, unique=True),
+                      keep_default=False)
+
+        # Adding field 'AnonymousUserSingleton.lock_id'
+        db.add_column(u'common_anonymoususersingleton', 'lock_id',
+                      self.gf('django.db.models.fields.CharField')(default=1, max_length=1, unique=True),
+                      keep_default=False)
+
+
+    models = {
+        u'auth.group': {
+            'Meta': {'object_name': 'Group'},
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
+            'permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': u"orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'})
+        },
+        u'auth.permission': {
+            'Meta': {'ordering': "(u'content_type__app_label', u'content_type__model', u'codename')", 'unique_together': "((u'content_type', u'codename'),)", 'object_name': 'Permission'},
+            'codename': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['contenttypes.ContentType']"}),
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        u'auth.user': {
+            'Meta': {'object_name': 'User'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'groups': ('django.db.models.fields.related.ManyToManyField', [], {'symmetrical': 'False', 'related_name': "u'user_set'", 'blank': 'True', 'to': u"orm['auth.Group']"}),
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
+            'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'symmetrical': 'False', 'related_name': "u'user_set'", 'blank': 'True', 'to': u"orm['auth.Permission']"}),
+            'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
+        },
+        u'common.anonymoususersingleton': {
+            'Meta': {'object_name': 'AnonymousUserSingleton'},
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'})
+        },
+        u'common.autoadminsingleton': {
+            'Meta': {'object_name': 'AutoAdminSingleton'},
+            'account': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'auto_admin_account'", 'null': 'True', 'to': u"orm['auth.User']"}),
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'password': ('django.db.models.fields.CharField', [], {'max_length': '128', 'null': 'True', 'blank': 'True'}),
+            'password_hash': ('django.db.models.fields.CharField', [], {'max_length': '128', 'null': 'True', 'blank': 'True'})
+        },
+        u'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        }
+    }
+
+    complete_apps = ['common']

mayan/apps/common/models.py

@@ -4,43 +4,10 @@ from django.utils.translation import ugettext
 from django.contrib.auth.models import AnonymousUser
 from django.contrib.auth.models import User
 
-SINGLETON_LOCK_ID = 1
+from solo.models import SingletonModel
 
 
-class SingletonManager(models.Manager):
+class AnonymousUserSingleton(SingletonModel):
-    def get(self, **kwargs):
-        instance, created = self.model.objects.get_or_create(lock_id=SINGLETON_LOCK_ID, **kwargs)
-        return instance
-
-
-class Singleton(models.Model):
-    lock_id = models.CharField(max_length=1, default=SINGLETON_LOCK_ID, editable=False, verbose_name=_(u'lock field'), unique=True)
-
-    objects = SingletonManager()
-
-    def save(self, *args, **kwargs):
-        self.id = 1
-        super(Singleton, self).save(*args, **kwargs)
-
-    def delete(self, force=False, *args, **kwargs):
-        if force:
-            return super(Singleton, self).delete(*args, **kwargs)
-
-    class Meta:
-        abstract = True
-
-
-class AnonymousUserSingletonManager(SingletonManager):
-    def passthru_check(self, user):
-        if isinstance(user, AnonymousUser):
-            return self.model.objects.get()
-        else:
-            return user
-
-
-class AnonymousUserSingleton(Singleton):
-    objects = AnonymousUserSingletonManager()
-
     def __unicode__(self):
         return ugettext('Anonymous user')
 
@@ -49,7 +16,7 @@ class AnonymousUserSingleton(Singleton):
         verbose_name_plural = _(u'anonymous user')
 
 
-class AutoAdminSingleton(Singleton):
+class AutoAdminSingleton(SingletonModel):
     account = models.ForeignKey(User, null=True, blank=True, related_name='auto_admin_account', verbose_name=_(u'account'))
     password = models.CharField(null=True, blank=True, verbose_name=_(u'password'), max_length=128)
     password_hash = models.CharField(null=True, blank=True, verbose_name=_(u'password hash'), max_length=128)

mayan/apps/installation/__init__.py

@@ -19,7 +19,7 @@ from .models import Installation
 @receiver(post_migrate, dispatch_uid='trigger_first_time')
 def trigger_first_time(sender, **kwargs):
     if kwargs['app'] == 'installation':
-        details = Installation.objects.get()
+        details, created = Installation.objects.get_or_create()
         details.is_first_run = True
         details.save()
 
@@ -27,7 +27,7 @@ def trigger_first_time(sender, **kwargs):
 def check_first_run():
     try:
         with transaction.atomic():
-            details = Installation.objects.get()
+            details, created = Installation.objects.get_or_create()
     except DatabaseError:
         # Avoid database errors when the app tables haven't been created yet
         pass

mayan/apps/installation/migrations/0002_auto__del_field_installation_lock_id.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Deleting field 'Installation.lock_id'
+        db.delete_column(u'installation_installation', 'lock_id')
+
+
+    def backwards(self, orm):
+        # Adding field 'Installation.lock_id'
+        db.add_column(u'installation_installation', 'lock_id',
+                      self.gf('django.db.models.fields.CharField')(default=1, max_length=1, unique=True),
+                      keep_default=False)
+
+
+    models = {
+        u'installation.installation': {
+            'Meta': {'object_name': 'Installation'},
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_first_run': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'uuid': ('django.db.models.fields.CharField', [], {'default': "u'745d2184-d011-4a19-a3d9-df3bab80f82c'", 'max_length': '48', 'blank': 'True'})
+        }
+    }
+
+    complete_apps = ['installation']

mayan/apps/installation/models.py

@@ -24,7 +24,8 @@ from django.utils.translation import ugettext_lazy as _
 from django.utils.datastructures import SortedDict
 from django.conf import settings
 
-from common.models import Singleton
+from solo.models import SingletonModel
+
 from common.utils import pretty_size
 from mayan import __version__ as mayan_version
 from lock_manager import Lock, LockError
@@ -35,7 +36,7 @@ from .literals import (FORM_SUBMIT_URL, FORM_KEY, FORM_RECEIVER_FIELD,
     TIMEOUT, FABFILE_MARKER)
 
 
-class Installation(Singleton):
+class Installation(SingletonModel):
     _properties = SortedDict()
 
     is_first_run = models.BooleanField(default=False)

mayan/apps/registration/__init__.py

@@ -20,6 +20,6 @@ register_links(['form_view', 'about_view', 'license_view'], [form_view], menu_na
 
 try:
     with transaction.atomic():
-        RegistrationSingleton.objects.get()
+        RegistrationSingleton.objects.get_or_create()
 except DatabaseError:
     pass

mayan/apps/registration/migrations/0002_auto__del_field_registrationsingleton_lock_id.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Deleting field 'RegistrationSingleton.lock_id'
+        db.delete_column(u'registration_registrationsingleton', 'lock_id')
+
+
+    def backwards(self, orm):
+        # Adding field 'RegistrationSingleton.lock_id'
+        db.add_column(u'registration_registrationsingleton', 'lock_id',
+                      self.gf('django.db.models.fields.CharField')(default=1, max_length=1, unique=True),
+                      keep_default=False)
+
+
+    models = {
+        u'registration.registrationsingleton': {
+            'Meta': {'object_name': 'RegistrationSingleton'},
+            u'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'registered': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'registration_data': ('django.db.models.fields.TextField', [], {'blank': 'True'})
+        }
+    }
+
+    complete_apps = ['registration']

mayan/apps/registration/models.py

@@ -6,14 +6,15 @@ import requests
 from django.db import models
 from django.utils.translation import ugettext_lazy as _
 
-from common.models import Singleton
+from solo.models import SingletonModel
+
 from lock_manager import Lock, LockError
 
 from .literals import FORM_SUBMIT_URL, FORM_KEY, FORM_RECEIVER_FIELD, TIMEOUT
 from .exceptions import AlreadyRegistered
 
 
-class RegistrationSingleton(Singleton):
+class RegistrationSingleton(SingletonModel):
     _cached_name = None
     _registered = None
 

mayan/settings.py

@@ -52,6 +52,7 @@ INSTALLED_APPS = (
     'mptt',
     'compressor',
     'rest_framework',
+    'solo',
 # Base generic
     'permissions',
     'project_setup',

requirements/common.txt

@@ -10,6 +10,7 @@ django-taggit==0.12
 django-mptt==0.6.1
 django-rest-swagger==0.1.14
 django-sendfile==0.3.6
+django-solo==1.0.5
 djangorestframework==2.3.14
 
 GitPython==0.3.2.RC1

setup.py

@@ -62,6 +62,7 @@ django-taggit==0.12
 django-mptt==0.6.1
 django-rest-swagger==0.1.14
 django-sendfile==0.3.6
+django-solo==1.0.5
 djangorestframework==2.3.14
 GitPython==0.3.2.RC1
 ghostscript==0.4.1