From b5ede7c2d3e3580ff37a62a256fe9de94e82feff Mon Sep 17 00:00:00 2001
From: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>
Date: Sat, 11 Jul 2015 03:45:38 -0400
Subject: [PATCH] Add auto increment order for transformations.

---
 mayan/apps/converter/forms.py                 | 11 ---------
 .../migrations/0006_auto_20150708_0120.py     |  2 +-
 .../migrations/0008_auto_20150711_0723.py     | 24 +++++++++++++++++++
 mayan/apps/converter/models.py                |  9 ++++++-
 4 files changed, 33 insertions(+), 13 deletions(-)
 delete mode 100644 mayan/apps/converter/forms.py
 create mode 100644 mayan/apps/converter/migrations/0008_auto_20150711_0723.py

diff --git a/mayan/apps/converter/forms.py b/mayan/apps/converter/forms.py
deleted file mode 100644
index 6c897cf27a..0000000000
--- a/mayan/apps/converter/forms.py
+++ /dev/null
@@ -1,11 +0,0 @@
-from __future__ import unicode_literals
-
-from django import forms
-
-from .models import Transformation
-
-
-class TransformationForm(forms.ModelForm):
-    class Meta:
-        fields = ('order', 'name', 'arguments')
-        model = Transformation
diff --git a/mayan/apps/converter/migrations/0006_auto_20150708_0120.py b/mayan/apps/converter/migrations/0006_auto_20150708_0120.py
index ca240ed57f..d77d536010 100644
--- a/mayan/apps/converter/migrations/0006_auto_20150708_0120.py
+++ b/mayan/apps/converter/migrations/0006_auto_20150708_0120.py
@@ -15,7 +15,7 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name='transformation',
             name='arguments',
-            field=models.TextField(help_text='Enter the arguments for the transformation as a YAML dictionary. ie: {"degrees": 180}', blank=True, verbose_name='Arguments', validators=converter.models.validators),
+            field=models.TextField(help_text='Enter the arguments for the transformation as a YAML dictionary. ie: {"degrees": 180}', blank=True, verbose_name='Arguments', validators=getattr(converter.models, 'validators', [])),
             preserve_default=True,
         ),
     ]
diff --git a/mayan/apps/converter/migrations/0008_auto_20150711_0723.py b/mayan/apps/converter/migrations/0008_auto_20150711_0723.py
new file mode 100644
index 0000000000..ccda029b85
--- /dev/null
+++ b/mayan/apps/converter/migrations/0008_auto_20150711_0723.py
@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('converter', '0007_auto_20150711_0656'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='transformation',
+            name='order',
+            field=models.PositiveIntegerField(default=0, help_text='Order in which the transformations will be executed.', db_index=True, verbose_name='Order', blank=True),
+            preserve_default=True,
+        ),
+        migrations.AlterUniqueTogether(
+            name='transformation',
+            unique_together=set([('content_type', 'object_id', 'order')]),
+        ),
+    ]
diff --git a/mayan/apps/converter/models.py b/mayan/apps/converter/models.py
index 4056a0f756..df52ad6747 100644
--- a/mayan/apps/converter/models.py
+++ b/mayan/apps/converter/models.py
@@ -5,6 +5,7 @@ import logging
 from django.contrib.contenttypes import generic
 from django.contrib.contenttypes.models import ContentType
 from django.db import models
+from django.db.models import Max
 from django.utils.encoding import python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
 
@@ -26,7 +27,7 @@ class Transformation(models.Model):
     object_id = models.PositiveIntegerField()
     content_object = generic.GenericForeignKey('content_type', 'object_id')
 
-    order = models.PositiveIntegerField(blank=True, db_index=True, default=0, help_text=_('Order in which the transformations will be executed.'), null=True, verbose_name=_('Order'))
+    order = models.PositiveIntegerField(blank=True, db_index=True, default=0, help_text=_('Order in which the transformations will be executed. If left unchanged, an automatic order value will be assigned.'), verbose_name=_('Order'))
     name = models.CharField(choices=BaseTransformation.get_transformation_choices(), max_length=128, verbose_name=_('Name'))
     arguments = models.TextField(blank=True, help_text=_('Enter the arguments for the transformation as a YAML dictionary. ie: {"degrees": 180}'), validators=[YAMLValidator()], verbose_name=_('Arguments'))
 
@@ -35,7 +36,13 @@ class Transformation(models.Model):
     def __str__(self):
         return self.get_name_display()
 
+    def save(self, *args, **kwargs):
+        if not self.order:
+            self.order = Transformation.objects.filter(content_type=self.content_type, object_id=self.object_id).aggregate(Max('order'))['order__max'] + 1
+        super(Transformation, self).save(*args, **kwargs)
+
     class Meta:
         ordering = ('order',)
+        unique_together = ('content_type', 'object_id', 'order')
         verbose_name = _('Transformation')
         verbose_name_plural = _('Transformations')