Added idempotent deploy support.

admin_interface/migrations/0014_name_unique.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('admin_interface', '0013_add_related_modal_close_button'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='theme',
+            name='name',
+            field=models.CharField(default='Django', max_length=50, unique=True, verbose_name='name'),
+        ),
+    ]

admin_interface/models.py

@@ -3,7 +3,7 @@
 from __future__ import unicode_literals
 
 from django.db import models
-from django.db.models.signals import post_delete, post_save
+from django.db.models.signals import post_delete, post_save, pre_save
 from django.utils.encoding import python_2_unicode_compatible, force_text
 from django.utils.translation import ugettext_lazy as _
 
@@ -27,6 +27,16 @@ class Theme(models.Model):
             Theme.objects.exclude(pk=instance.pk).update(active=False)
         Theme.get_active_theme()
 
+    @staticmethod
+    def pre_save_handler(instance, **kwargs):
+        if instance.pk is None:
+            try:
+                obj = Theme.objects.get(name=instance.name)
+                if obj:
+                    instance.pk = obj.pk
+            except Theme.DoesNotExist:
+                pass
+
     @staticmethod
     def get_active_theme():
         objs_manager = Theme.objects
@@ -51,6 +61,7 @@ class Theme(models.Model):
         return obj
 
     name = models.CharField(
+        unique=True,
         max_length=50,
         default='Django',
         verbose_name=_('name'))
@@ -275,3 +286,4 @@ class Theme(models.Model):
 
 post_delete.connect(Theme.post_delete_handler, sender=Theme)
 post_save.connect(Theme.post_save_handler, sender=Theme)
+pre_save.connect(Theme.pre_save_handler, sender=Theme)