Fixes error in EnablingConditionBase, adds admins for Product and Category enabling conditions

registrasion/admin.py

@@ -80,3 +80,15 @@ class VoucherAdmin(nested_admin.NestedAdmin):
         VoucherDiscountInline,
         VoucherEnablingConditionInline,
     ]
+
+
+# Enabling conditions
+@admin.register(rego.ProductEnablingCondition)
+class ProductEnablingConditionAdmin(nested_admin.NestedAdmin):
+    model = rego.ProductEnablingCondition
+
+
+# Enabling conditions
+@admin.register(rego.CategoryEnablingCondition)
+class CategoryEnablingConditionAdmin(nested_admin.NestedAdmin):
+    model = rego.CategoryEnablingCondition

registrasion/migrations/0001_squashed_0002_auto_20160304_1723.py

@@ -9,6 +9,8 @@ from django.conf import settings
 
 class Migration(migrations.Migration):
 
+    replaces = [('registrasion', '0001_initial'), ('registrasion', '0002_auto_20160304_1723')]
+
     dependencies = [
         migrations.swappable_dependency(settings.AUTH_USER_MODEL),
     ]
@@ -225,12 +227,12 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='enablingconditionbase',
             name='categories',
-            field=models.ManyToManyField(to=b'registrasion.Category'),
+            field=models.ManyToManyField(to=b'registrasion.Category', blank=True),
         ),
         migrations.AddField(
             model_name='enablingconditionbase',
             name='products',
-            field=models.ManyToManyField(to=b'registrasion.Product'),
+            field=models.ManyToManyField(to=b'registrasion.Product', blank=True),
         ),
         migrations.AddField(
             model_name='discountitem',

registrasion/models.py

@@ -257,8 +257,8 @@ class EnablingConditionBase(models.Model):
 
     description = models.CharField(max_length=255)
     mandatory = models.BooleanField(default=False)
-    products = models.ManyToManyField(Product)
-    categories = models.ManyToManyField(Category)
+    products = models.ManyToManyField(Product, blank=True)
+    categories = models.ManyToManyField(Category, blank=True)
 
 
 class TimeOrStockLimitEnablingCondition(EnablingConditionBase):