Added nb_versions field, auto compute number of versions and tests #55

backend/backend_app/migrations/0002_auto_20190310_1726.py

+# Generated by Django 2.1.7 on 2019-03-10 16:26
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('backend_app', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='campus',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='campustaggeditem',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='citytaggeditem',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='countrydri',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='countryscholarship',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='countrytaggeditem',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='fortestingversioning',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='universitydri',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='universityinfo',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='universityscholarship',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='universitysemestersdates',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='universitytaggeditem',
+            name='nb_version',
+            field=models.PositiveIntegerField(default=0),
+        ),
+    ]

backend/backend_app/migrations/0003_auto_20190310_1731.py

+# Generated by Django 2.1.7 on 2019-03-10 16:31
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('backend_app', '0002_auto_20190310_1726'),
+    ]
+
+    operations = [
+        migrations.RenameField(
+            model_name='campus',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+        migrations.RenameField(
+            model_name='campustaggeditem',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+        migrations.RenameField(
+            model_name='citytaggeditem',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+        migrations.RenameField(
+            model_name='countrydri',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+        migrations.RenameField(
+            model_name='countryscholarship',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+        migrations.RenameField(
+            model_name='countrytaggeditem',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+        migrations.RenameField(
+            model_name='fortestingversioning',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+        migrations.RenameField(
+            model_name='universitydri',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+        migrations.RenameField(
+            model_name='universityinfo',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+        migrations.RenameField(
+            model_name='universityscholarship',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+        migrations.RenameField(
+            model_name='universitysemestersdates',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+        migrations.RenameField(
+            model_name='universitytaggeditem',
+            old_name='nb_version',
+            new_name='nb_versions',
+        ),
+    ]

backend/backend_app/models/abstract/my_model/myModelVersionned.py

 from django.contrib.contenttypes.models import ContentType
 from django.core import serializers as djangoSerializers
 from django.core.serializers.base import DeserializationError
+from django.db import models
 
 import reversion
 from backend_app.custom import MySerializerWithJSON
@@ -20,6 +21,9 @@ class MyModelVersionned(MyModel):
     Custom MyModel that will be versionned in the app
     """
 
+    # We store the current number of versions for better performance
+    nb_versions = models.PositiveIntegerField(default=0)
+
     @classmethod
     def get_serializer(cls):
         """
@@ -39,20 +43,11 @@ class MyModelVersionnedSerializer(MyModelSerializer):
     """
 
     # Add a nb_versions field
-    nb_versions = serializers.SerializerMethodField()
+    nb_versions = serializers.IntegerField(read_only=True)
+
     # Add a content_type_id field to be able to find versions
     content_type_id = serializers.SerializerMethodField()
 
-    def get_nb_versions(self, obj):
-        """
-        Serializer for the nb_version field
-        With a bit of optimization
-        """
-        if self.FORCE_FULL_DISPLAY or self.context["view"].action != "list":
-            versions = Version.objects.get_for_object(obj)
-            return len(versions)
-        return None
-
     def get_content_type_id(self, obj):
         """
         Serializer for content type

backend/backend_app/signals/__squash_revision_by_user.py

@@ -24,6 +24,11 @@ def squash_revision_by_user(sender, obj, **kwargs):
             else:
                 break
 
+    # We update the number of versions directly here
+    # So that it doesn't have to be recomputed every time
+    obj.nb_versions = len(Version.objects.get_for_object(obj))
+    obj.save()
+
 
 new_revision_saved.connect(
     squash_revision_by_user, dispatch_uid="receiver_concat_revisions"

backend/backend_app/tests/test_squash_versions.py

@@ -27,6 +27,7 @@ class SquashVersionsTestCase(WithUserTestCase):
         """
         Test to check that when two different users successively
         Modify a model, no squashing is performed
+        nb_versions is incremented
         """
         with reversion.create_revision():
             self.obj.bbb = "v2 other user"
@@ -37,6 +38,7 @@ class SquashVersionsTestCase(WithUserTestCase):
 
         versions = self.get_versions(self.obj)
         self.assertEqual(len(versions), 2)
+        self.assertEqual(len(versions), self.obj.nb_versions)
         first_edit = self.get_version_data(versions[1])
         second_edit = self.get_version_data(versions[0])
 
@@ -46,7 +48,8 @@ class SquashVersionsTestCase(WithUserTestCase):
     def test_squashing(self):
         """
         Test to check that when a user save two different
-        versions of a same model, no squashing is performed
+        versions of a same model, squashing is performed
+        nb_versions is not incremented
         """
         with reversion.create_revision():
             self.obj.bbb = "v2"
@@ -57,5 +60,6 @@ class SquashVersionsTestCase(WithUserTestCase):
 
         versions = self.get_versions(self.obj)
         self.assertEqual(len(versions), 1)
+        self.assertEqual(len(versions), self.obj.nb_versions)
         version_data = self.get_version_data(versions[0])
         self.assertEqual(version_data["bbb"], "v2")

backend/backend_app/tests/test_versionning.py

@@ -37,6 +37,7 @@ class VersioningTestCase(WithUserTestCase):
         """
         Test to check that versioning is working
         We also check that new_revision_saved is called
+        We also check that the number of versions in the field is incremented
         """
 
         def _test_signal_sent(sender, obj, **kwargs):
@@ -53,6 +54,7 @@ class VersioningTestCase(WithUserTestCase):
 
         versions = Version.objects.get_for_object(instance)
         self.assertEqual(len(versions), 1)
+        self.assertEqual(len(versions), instance.nb_versions)
         self.assertTrue(self.signal_was_called)
         self.reset_signal_called()
 
@@ -62,6 +64,8 @@ class VersioningTestCase(WithUserTestCase):
         )
         self.assertEqual(response.status_code, 200)
 
+        instance = self._test_retreive_instance(data_2)
         versions = Version.objects.get_for_object(instance)
         self.assertEqual(len(versions), 2)
+        self.assertEqual(len(versions), instance.nb_versions)
         self.assertTrue(self.signal_was_called)