Replace auto_now and auto_now_add with defaults which can be overridden

.gitignore

@@ -15,6 +15,5 @@ celerybeat-schedule
 
 *.DS_Store
 .tox/
-test-runner/env/
-test-runner/smartmin
 csv_imports/
+!smartmin/csv_imports/

smartmin/csv_imports/migrations/0004_auto_20170223_0917.py

@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.4 on 2017-02-23 09:17
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.utils.timezone
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('csv_imports', '0003_importtask_task_status'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='importtask',
+            name='created_on',
+            field=models.DateTimeField(blank=True, default=django.utils.timezone.now, editable=False, help_text='When this item was originally created'),
+        ),
+        migrations.AlterField(
+            model_name='importtask',
+            name='modified_on',
+            field=models.DateTimeField(blank=True, default=django.utils.timezone.now, editable=False, help_text='When this item was last modified'),
+        ),
+    ]

smartmin/models.py

@@ -7,7 +7,6 @@
 import pytz
 import six
 
-from six import text_type
 from django.conf import settings
 from django.db import models
 from django.utils import timezone
@@ -37,15 +36,23 @@ class SmartModel(models.Model):
     created_by = models.ForeignKey(settings.AUTH_USER_MODEL,
                                    related_name="%(app_label)s_%(class)s_creations",
                                    help_text="The user which originally created this item")
-    created_on = models.DateTimeField(auto_now_add=True,
+    created_on = models.DateTimeField(default=timezone.now, editable=False, blank=True,
                                       help_text="When this item was originally created")
 
     modified_by = models.ForeignKey(settings.AUTH_USER_MODEL,
                                     related_name="%(app_label)s_%(class)s_modifications",
                                     help_text="The user which last modified this item")
-    modified_on = models.DateTimeField(auto_now=True,
+    modified_on = models.DateTimeField(default=timezone.now, editable=False, blank=True,
                                        help_text="When this item was last modified")
 
+    def save(self, *args, **kwargs):
+        update_fields = kwargs.get('update_fields', None)
+
+        if (update_fields is None or 'modified_on' in update_fields) and not kwargs.pop('preserve_modified_on', False):
+            self.modified_on = timezone.now()
+
+        return super(SmartModel, self).save(*args, **kwargs)
+
     class Meta:
         abstract = True
 
@@ -240,12 +247,12 @@ def import_xls(cls, filename, user, import_params, log=None, import_results=None
                         num_errors += 1
 
                 except SmartImportRowError as e:
-                    error_messages.append(dict(line=line_number+1, error=text_type(e)))
+                    error_messages.append(dict(line=line_number+1, error=six.text_type(e)))
 
                 except Exception as e:
                     if log:
                         traceback.print_exc(100, log)
-                    raise Exception("Line %d: %s\n\n%s" % (line_number, text_type(e), field_values))
+                    raise Exception("Line %d: %s\n\n%s" % (line_number, six.text_type(e), field_values))
                 line_number += 1
             # only care about the first sheet
             break

test_runner/blog/migrations/0003_auto_20170223_0917.py

@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.4 on 2017-02-23 09:17
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.utils.timezone
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('blog', '0002_post_uuid'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='category',
+            name='created_on',
+            field=models.DateTimeField(blank=True, default=django.utils.timezone.now, editable=False, help_text='When this item was originally created'),
+        ),
+        migrations.AlterField(
+            model_name='category',
+            name='modified_on',
+            field=models.DateTimeField(blank=True, default=django.utils.timezone.now, editable=False, help_text='When this item was last modified'),
+        ),
+        migrations.AlterField(
+            model_name='post',
+            name='created_on',
+            field=models.DateTimeField(blank=True, default=django.utils.timezone.now, editable=False, help_text='When this item was originally created'),
+        ),
+        migrations.AlterField(
+            model_name='post',
+            name='modified_on',
+            field=models.DateTimeField(blank=True, default=django.utils.timezone.now, editable=False, help_text='When this item was last modified'),
+        ),
+    ]

test_runner/blog/tests.py

@@ -317,20 +317,58 @@ def test_management(self):
         self.assertEquals(12, authors.permissions.all().count())
 
     def test_smart_model(self):
-        Post.objects.create(title="First Post", body="First Post body", order=1, tags="first",
-                            created_by=self.author, modified_by=self.author)
-        p2 = Post.objects.create(title="Second Post", body="Second Post body", order=1, tags="second",
+        d1 = datetime(2016, 12, 31, 9, 20, 30, 123456, tzinfo=pytz.timezone("Africa/Kigali"))
+        d2 = datetime(2017, 1, 10, 10, 20, 30, 123456, tzinfo=pytz.timezone("Africa/Kigali"))
+        d3 = timezone.now()
+
+        p1 = Post.objects.create(title="First Post", body="First Post body", order=1, tags="first",
                                  created_by=self.author, modified_by=self.author)
+        p2 = Post.objects.create(title="Second Post", body="Second Post body", order=1, tags="second",
+                                 created_on=d1, created_by=self.author,
+                                 modified_on=d2, modified_by=self.author)
+        p3 = Post(title="Third Post", body="Third Post body", order=1, tags="third",
+                  created_on=d1, created_by=self.author,
+                  modified_on=d2, modified_by=self.author)
+        p3.save(preserve_modified_on=True)
+
+        self.assertGreater(p1.created_on, d3)  # defaults to current time
+        self.assertGreater(p1.modified_on, d3)  # defaults to current time
+
+        self.assertEqual(p2.created_on, d1)  # uses provided time
+        self.assertGreater(p2.modified_on, d3)  # ignores provided time (equivalent to auto_now)
+
+        self.assertEqual(p3.created_on, d1)  # uses provided time
+        self.assertEqual(p3.modified_on, d2)  # uses provided time
+
+        d4 = timezone.now()
+
+        p1.save()
+        p2.save(update_fields=('title',))
+        p3.save(update_fields=('title', 'modified_on'))
+        self.post.save(preserve_modified_on=True)
+
+        self.assertLess(p1.created_on, d4)  # not updated
+        self.assertGreater(p1.modified_on, d4)  # updated by save with no args
+
+        self.assertLess(p2.created_on, d4)  # not updated
+        self.assertLess(p2.modified_on, d4)  # not updated because excluded by update_fields arg
+
+        self.assertLess(p3.created_on, d4)  # not updated
+        self.assertGreater(p3.modified_on, d4)  # updated because included by update_fields arg
+
+        self.assertLess(self.post.created_on, d4)  # not updated
+        self.assertLess(self.post.modified_on, d4)  # not updated because preserve_modified_on arg
 
-        self.assertEquals(3, Post.objects.all().count())
-        self.assertEquals(3, Post.active.all().count())
+        # test object managers
+        self.assertEqual(Post.objects.all().count(), 4)
+        self.assertEqual(Post.active.all().count(), 4)
 
         # make p2 inactive
         p2.is_active = False
         p2.save()
 
-        self.assertEquals(3, Post.objects.all().count())
-        self.assertEquals(2, Post.active.all().count())
+        self.assertEqual(Post.objects.all().count(), 4)
+        self.assertEqual(Post.active.all().count(), 3)
 
     def test_get_import_file_headers(self):
         with open('test_runner/blog/test_files/posts.csv', 'rb') as open_file: