[#90] Use grouping instead of window function to also support django1…

….11 and stop using postgres as test db and use sqlite3 back again

.travis.yml

@@ -1,6 +1,4 @@
 language: python
-services:
-  - docker
 sudo: false
 cache: pip
 matrix:

requirements.txt

@@ -1,6 +1,5 @@
-django-mptt
-factory-boy
-mock
-pyhamcrest
-django-cte
-psycopg2
+django-mptt==0.9.1
+factory-boy==2.11.1
+mock==2.0.0
+pyhamcrest==1.9.0
+django-cte==1.1.4

river/core/classworkflowobject.py

@@ -1,7 +1,7 @@
 from django.contrib import auth
 from django.contrib.contenttypes.models import ContentType
-from django.db.models import Window, F, Q, IntegerField
-from django.db.models.functions import Rank, Cast
+from django.db.models import F, Q, IntegerField, Min
+from django.db.models.functions import Cast
 from django_cte import With
 
 from river.models import State, TransitionApprovalMeta, TransitionApproval, PENDING, Workflow
@@ -27,29 +27,37 @@ def get_on_approval_objects(self, as_user):
         return self.wokflow_object_class.objects.filter(pk__in=object_ids)
 
     def get_available_approvals(self, as_user):
-        approvals_with_priority_rank = With(
-            TransitionApproval.objects.filter(workflow=self.workflow, status=PENDING, skipped=False, enabled=True).annotate(
-                priority_rank=Window(
-                    expression=Rank(),
-                    order_by=F('priority').asc(),
-                    partition_by=[F('workflow'), F('object_id'), F('source_state'), F('destination_state')])
-            )
+        those_with_max_priority = With(
+            TransitionApproval.objects.filter(
+                workflow=self.workflow, status=PENDING, skipped=False, enabled=True
+            ).values(
+                'workflow', 'object_id', 'source_state', 'destination_state'
+            ).annotate(min_priority=Min('priority'))
         )
 
         workflow_objects = With(
             self.wokflow_object_class.objects.all(),
             name="workflow_object"
         )
 
-        approvals_after_ranking = approvals_with_priority_rank \
-            .join(self._authorized_approvals(as_user), id=approvals_with_priority_rank.col.id) \
-            .with_cte(approvals_with_priority_rank) \
-            .annotate(object_id_as_int=Cast('object_id', IntegerField()), priority_rank=approvals_with_priority_rank.col.priority_rank) \
-            .filter(priority_rank=1)
-
-        return workflow_objects.join(approvals_after_ranking, object_id_as_int=workflow_objects.col.pk) \
-            .with_cte(workflow_objects) \
-            .filter(source_state=getattr(workflow_objects.col, self.field_name + "_id"))
+        approvals_with_max_priority = those_with_max_priority.join(
+            self._authorized_approvals(as_user),
+            workflow_id=those_with_max_priority.col.workflow_id,
+            object_id=those_with_max_priority.col.object_id,
+            source_state_id=those_with_max_priority.col.source_state_id,
+            destination_state_id=those_with_max_priority.col.destination_state_id,
+        ).with_cte(
+            those_with_max_priority
+        ).annotate(
+            object_id_as_int=Cast('object_id', IntegerField()),
+            min_priority=those_with_max_priority.col.min_priority
+        ).filter(min_priority=F("priority"))
+
+        return workflow_objects.join(
+            approvals_with_max_priority, object_id_as_int=workflow_objects.col.pk
+        ).with_cte(
+            workflow_objects
+        ).filter(source_state=getattr(workflow_objects.col, self.field_name + "_id"))
 
     @property
     def initial_state(self):

river/core/instanceworkflowobject.py

@@ -31,7 +31,7 @@ def __init__(self, workflow_object, name, field_name):
     def initialize_approvals(self):
         if not self.initialized:
             workflow = Workflow.objects.filter(content_type=self.content_type, field_name=self.field_name).first()
-            if workflow and workflow.transition_approvals.count() == 0:
+            if workflow and workflow.transition_approvals.filter(workflow_object=self.workflow_object).count() == 0:
                 transition_approval_metas = workflow.transition_approval_metas.all()
                 meta_dict = six.moves.reduce(
                     lambda agg, meta: dict(agg, **{self._to_key(meta.source_state): agg.get(self._to_key(meta.source_state), []) + [meta]}),

river/migrations/0001_initial.py

@@ -11,9 +11,7 @@ class Migration(migrations.Migration):
     initial = True
 
     dependencies = [
-        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
-        ('contenttypes', '0002_remove_content_type_name'),
-        ('auth', '0009_alter_user_last_name_max_length'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL)
     ]
 
     operations = [

test_settings.py

@@ -9,29 +9,29 @@
 
 DEBUG = True
 
-# DATABASES = {
-#     'default': {
-#         'ENGINE': 'django.db.backends.sqlite3',
-#         'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
-#     },
-# }
-
-
-TEST_DB_PORT = os.environ['POSTGRES_5432_TCP_PORT']
 DATABASES = {
     'default': {
-        'ENGINE': 'django.db.backends.postgresql_psycopg2',
-        'NAME': 'river',
-        'USER': 'river',
-        'PASSWORD': 'river',
-        'HOST': 'localhost',
-        'PORT': TEST_DB_PORT,
-        'TEST': {
-            'NAME': 'test-db' + str(uuid4()),
-        },
-    }
+        'ENGINE': 'django.db.backends.sqlite3',
+        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
+    },
 }
 
+
+# TEST_DB_PORT = os.environ['POSTGRES_5432_TCP_PORT']
+# DATABASES = {
+#     'default': {
+#         'ENGINE': 'django.db.backends.postgresql_psycopg2',
+#         'NAME': 'river',
+#         'USER': 'river',
+#         'PASSWORD': 'river',
+#         'HOST': 'localhost',
+#         'PORT': TEST_DB_PORT,
+#         'TEST': {
+#             'NAME': 'test-db' + str(uuid4()),
+#         },
+#     }
+# }
+
 # DATABASES = {
 #     'default': {
 #         'ENGINE': 'django.db.backends.postgresql_psycopg2',  # Add 'postgresql_psycopg2', 'mysql', 'sqlite3' or 'oracle'.

tox.ini

@@ -1,36 +1,26 @@
 [tox]
-envlist = {py27,py34}-{dj1.7,dj1.8,dj1.9,dj1.10,dj1.11},
-          {py35}-{dj1.8,dj1.9,dj1.10,dj1.11,dj2.0,dj2.1},
-          {py36}-{dj1.8,dj1.9,dj1.10,dj1.11,dj2.0,dj2.1},
+envlist = {py27,py34}-{dj1.11},
+          {py35}-{dj1.11,dj2.0,dj2.1,dj2.2},
+          {py36}-{dj1.11,dj2.0,dj2.1,dj2.2},
           cov
 
 [testenv]
-docker =
-    postgres:11.5-alpine
-dockerenv =
-    POSTGRES_DB=river
-    POSTGRES_USER=river
-    POSTGRES_PASSWORD=river
 deps =
-    dj1.7: pytest-django==3.1.2
-    {dj1.8,dj1.9,dj1.10,dj1.11,dj2.0,dj2.1}: pytest-django>3.1.2
+    {dj1.11,dj2.0,dj2.1,dj2.2}: pytest-django>3.1.2
     pytest-cov
     -rrequirements.txt
-    dj1.7: Django>=1.7,<1.8.0
-    dj1.8: Django>=1.8,<1.9.0
-    dj1.9: Django>=1.9,<1.10.0
-    dj1.10: Django>=1.10,<1.11.0
     dj1.11: Django>=1.11,<1.12.0
     dj2.0: Django>=2.0,<2.1.0
     dj2.1: Django>=2.1,<2.2.0
+    dj2.2: Django>=2.2,<2.3.0
 commands = py.test --ds='test_settings' --junitxml=../junit-{envname}.xml
 
 [testenv:cov]
 basepython = python3.6
 deps =
     pytest-django
     pytest-cov
-    django>=2.1,<2.2.0
+    django>=2.2,<2.3.0
     -rrequirements.txt
 commands =
     py.test --ds='test_settings' --cov ./ --cov-report term-missing