Refactored sortable_by into a property instead of a classmethod.

Added backwards compatibility for pre 1.1.1 versions that still have sortable_by defined as a classmethod.
Need to address dynamic regroup template tag to see why categories are not being grouped properly in sample app.

adminsortable/admin.py

@@ -53,13 +53,18 @@ class SortableAdmin(ModelAdmin):
         has_perm = request.user.has_perm(opts.app_label + '.' + opts.get_change_permission())
         objects = self.model.objects.all()
 
-        """
+        #Determine if we need to regroup objects relative to a foreign key specified on the
-        Determine if we need to regroup objects relative to a foreign key specified on the
+        # model class that is extending Sortable.
-        model class that is extending Sortable.
-        """
         sortable_by = getattr(self.model, 'sortable_by', None)
         if sortable_by:
+            #backwards compatibility for < 1.1.1, where sortable_by was a classmethod instead of a property
+            try:
                 sortable_by_class, sortable_by_expression = sortable_by()
+            except ValueError:
+                sortable_by_class = self.model.sortable_by
+                sortable_by_expression = sortable_by_class.__name__.lower()
+
+            print sortable_by_expression
             sortable_by_class_display_name = sortable_by_class._meta.verbose_name_plural
             sortable_by_class_is_sortable = sortable_by_class.is_sortable()
         else:

adminsortable/models.py

@@ -14,8 +14,12 @@ class Sortable(models.Model):
     `model_type_id` returns the ContentType.id for the Model that inherits Sortable
 
     `save` the override of save increments the last/highest value of order by 1
+
+    Override `sortable_by` method to make your model be sortable by a foreign key field.
+    Set `sortable_by` to the class specified in the foreign key relationship.
     """
     order = models.PositiveIntegerField(editable=False, default=1, db_index=True)
+    sortable_by = None
 
     class Meta:
         abstract = True

adminsortable/templatetags/django_template_additions.py

@@ -69,7 +69,7 @@ def dynamic_regroup(parser, token):
     """
     expression = lastbits_reversed[2][::-1]
     var_name = lastbits_reversed[0][::-1]
-
+    print expression
     """
     We also need to hand the parser to the node in order to convert the value
     for `expression` to a FilterExpression.

sample_project/app/admin.py

@@ -1,7 +1,7 @@
 from django.contrib import admin
 
 from adminsortable.admin import SortableAdmin, SortableTabularInline, SortableStackedInline
-from app.models import Category, Project, Credit, Note
+from app.models import Category, Project, Credit, Note, Sample
 
 
 admin.site.register(Category, SortableAdmin)
@@ -20,3 +20,4 @@ class ProjectAdmin(SortableAdmin):
     list_display = ['__unicode__', 'category']
 
 admin.site.register(Project, ProjectAdmin)
+admin.site.register(Sample, SortableAdmin)

sample_project/app/migrations/0003_add_sample.py

@@ -0,0 +1,68 @@
+# encoding: utf-8
+import 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 'Sample'
+        db.create_table('app_sample', (
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('order', self.gf('django.db.models.fields.PositiveIntegerField')(default=1, db_index=True)),
+            ('title', self.gf('django.db.models.fields.CharField')(max_length=50)),
+            ('category', self.gf('django.db.models.fields.related.ForeignKey')(to=orm['app.Category'])),
+            ('description', self.gf('django.db.models.fields.TextField')()),
+        ))
+        db.send_create_signal('app', ['Sample'])
+
+
+    def backwards(self, orm):
+        
+        # Deleting model 'Sample'
+        db.delete_table('app_sample')
+
+
+    models = {
+        'app.category': {
+            'Meta': {'ordering': "['order']", 'object_name': 'Category'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'order': ('django.db.models.fields.PositiveIntegerField', [], {'default': '1', 'db_index': 'True'}),
+            'title': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'app.credit': {
+            'Meta': {'ordering': "['order']", 'object_name': 'Credit'},
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30'}),
+            'order': ('django.db.models.fields.PositiveIntegerField', [], {'default': '1', 'db_index': 'True'}),
+            'project': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['app.Project']"})
+        },
+        'app.note': {
+            'Meta': {'ordering': "['order']", 'object_name': 'Note'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'order': ('django.db.models.fields.PositiveIntegerField', [], {'default': '1', 'db_index': 'True'}),
+            'project': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['app.Project']"}),
+            'text': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        'app.project': {
+            'Meta': {'ordering': "['order']", 'object_name': 'Project'},
+            'category': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['app.Category']"}),
+            'description': ('django.db.models.fields.TextField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'order': ('django.db.models.fields.PositiveIntegerField', [], {'default': '1', 'db_index': 'True'}),
+            'title': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'app.sample': {
+            'Meta': {'ordering': "['order']", 'object_name': 'Sample'},
+            'category': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['app.Category']"}),
+            'description': ('django.db.models.fields.TextField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'order': ('django.db.models.fields.PositiveIntegerField', [], {'default': '1', 'db_index': 'True'}),
+            'title': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        }
+    }
+
+    complete_apps = ['app']

sample_project/app/models.py

@@ -29,13 +29,28 @@ class Project(SimpleModel, Sortable):
     class Meta(Sortable.Meta):
         pass
 
-    @classmethod
+#    @classmethod
-    def sortable_by(cls):
+#    def sortable_by(cls):
-        return Category, 'category'
+#        return Category, 'category'
 
     category = models.ForeignKey(Category)
     description = models.TextField()
 
+    sortable_by = Category
+
+
+#a model that is sortable relative to a foreign key that is also sortable
+class Sample(SimpleModel, Sortable):
+    class Meta(Sortable.Meta):
+        pass
+
+    category = models.ForeignKey(Category)
+    description = models.TextField()
+
+    #field to define which foreign key the model is sortable by.
+    #works with versions > 1.1.1
+    sortable_by = Category
+
 
 #registered as a tabular inline on project
 class Credit(Sortable):

sample_project/app/tests.py

@@ -1,12 +1,9 @@
 import httplib
 import json
 
-from django.contrib.auth.forms import authenticate, UserCreationForm
 from django.contrib.auth.models import User
 from django.core.urlresolvers import reverse
-from django.middleware import csrf
 from django.db import models
-from django.template.defaultfilters import urlencode
 from django.test import TestCase
 from django.test.client import Client, RequestFactory
 
@@ -83,6 +80,9 @@ class SortableTestCase(TestCase):
     def get_category_indexes(self, *categories):
         return {'indexes' : ','.join([str(c.id) for c in categories])}
 
+    def test_sortable_by_backwards_compatibility(self):
+        pass
+
     def test_adminsortable_changelist_templates(self):
         logged_in = self.client.login(username=self.user.username, password=self.user_raw_password)
         self.assertTrue(logged_in, 'User is not logged in')

sample_project/settings.py

@@ -102,7 +102,6 @@ MIDDLEWARE_CLASSES = (
     'django.middleware.csrf.CsrfViewMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
     'django.contrib.messages.middleware.MessageMiddleware',
-    'debug_toolbar.middleware.DebugToolbarMiddleware',
 )
 
 TEMPLATE_CONTEXT_PROCESSORS = (