Prevent generation of useless migrations upon settings change

club/migrations/0011_auto_20180426_2013.py

+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import club.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('club', '0010_auto_20170912_2028'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='club',
+            name='owner_group',
+            field=models.ForeignKey(default=club.models.Club.get_default_owner_group, related_name='owned_club', to='core.Group'),
+        ),
+    ]

club/models.py

@@ -62,9 +62,9 @@ class Club(models.Model):
     is_active = models.BooleanField(_('is active'), default=True)
     short_description = models.CharField(_('short description'), max_length=1000, default='', blank=True, null=True)
     address = models.CharField(_('address'), max_length=254)
-    # email = models.EmailField(_('email address'), unique=True) # This should, and will be generated automatically
-    owner_group = models.ForeignKey(Group, related_name="owned_club",
-                                    default=settings.SITH_GROUP_ROOT_ID)
+    # This function prevents generating migration upon settings change
+    def get_default_owner_group(): return settings.SITH_GROUP_ROOT_ID
+    owner_group = models.ForeignKey(Group, related_name="owned_club", default=get_default_owner_group)
     edit_groups = models.ManyToManyField(Group, related_name="editable_club", blank=True)
     view_groups = models.ManyToManyField(Group, related_name="viewable_club", blank=True)
     home = models.OneToOneField(SithFile, related_name='home_of_club', verbose_name=_("home"), null=True, blank=True,

core/migrations/0029_auto_20180426_2013.py

+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import core.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0028_auto_20171216_2044'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='page',
+            name='owner_group',
+            field=models.ForeignKey(verbose_name='owner group', default=core.models.Page.get_default_owner_group, related_name='owned_page', to='core.Group'),
+        ),
+    ]

core/models.py

@@ -920,8 +920,10 @@ class Page(models.Model):
     # Attention: this field may not be valid until you call save(). It's made for fast query, but don't rely on it when
     # playing with a Page object, use get_full_name() instead!
     _full_name = models.CharField(_('page name'), max_length=255, blank=True)
+    # This function prevents generating migration upon settings change
+    def get_default_owner_group(): return settings.SITH_GROUP_ROOT_ID
     owner_group = models.ForeignKey(Group, related_name="owned_page", verbose_name=_("owner group"),
-                                    default=settings.SITH_GROUP_ROOT_ID)
+                                    default=get_default_owner_group)
     edit_groups = models.ManyToManyField(Group, related_name="editable_page", verbose_name=_("edit group"), blank=True)
     view_groups = models.ManyToManyField(Group, related_name="viewable_page", verbose_name=_("view group"), blank=True)
     lock_user = models.ForeignKey(User, related_name="locked_pages", verbose_name=_("lock user"), blank=True, null=True, default=None)

forum/migrations/0006_auto_20180426_2013.py

+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import forum.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('forum', '0005_forumtopic_subscribed_users'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='forum',
+            name='edit_groups',
+            field=models.ManyToManyField(blank=True, default=forum.models.Forum.get_default_edit_group, related_name='editable_forums', to='core.Group'),
+        ),
+        migrations.AlterField(
+            model_name='forum',
+            name='view_groups',
+            field=models.ManyToManyField(blank=True, default=forum.models.Forum.get_default_view_group, related_name='viewable_forums', to='core.Group'),
+        ),
+    ]

forum/models.py

@@ -38,6 +38,7 @@ from core.models import User, Group
 from club.models import Club
 
 
+
 class Forum(models.Model):
     """
     The Forum class, made as a tree to allow nice tidy organization
@@ -46,6 +47,9 @@ class Forum(models.Model):
     edit_groups allows to put any group as a forum admin
     view_groups allows some groups to view a forum
     """
+    # Those functions prevent generating migration upon settings changes
+    def get_default_edit_group(): return [settings.SITH_GROUP_OLD_SUBSCRIBERS_ID]
+    def get_default_view_group(): return [settings.SITH_GROUP_PUBLIC_ID]
     id = models.AutoField(primary_key=True, db_index=True)
     name = models.CharField(_('name'), max_length=64)
     description = models.CharField(_('description'), max_length=512, default="")
@@ -54,9 +58,9 @@ class Forum(models.Model):
     owner_club = models.ForeignKey(Club, related_name="owned_forums", verbose_name=_("owner club"),
                                    default=settings.SITH_MAIN_CLUB_ID)
     edit_groups = models.ManyToManyField(Group, related_name="editable_forums", blank=True,
-                                         default=[settings.SITH_GROUP_OLD_SUBSCRIBERS_ID])
+                                         default=get_default_edit_group)
     view_groups = models.ManyToManyField(Group, related_name="viewable_forums", blank=True,
-                                         default=[settings.SITH_GROUP_PUBLIC_ID])
+                                         default=get_default_view_group)
     number = models.IntegerField(_("number to choose a specific forum ordering"), default=1)
     _last_message = models.ForeignKey('ForumMessage', related_name="forums_where_its_last",
                                       verbose_name=_("the last message"), null=True, on_delete=models.SET_NULL)