Support inheritance override for handlers

CHANGELOG.rst

@@ -2,6 +2,13 @@
 Changelog
 =========
 
+1.8.0 2021-01-07
+----------------
+
+* Clean Django 4.0 warnings
+* Allow flow.Handler redifinition with inheritance 
+
+
 1.7.0 2020-11-18
 ----------------
 

README.rst

@@ -28,7 +28,8 @@ http://viewflow.io.
 - Viewflow 1.1.x compatible with Django 1.8/1.9/1.10/1.11 (supported till Django 1.8 lifetime/April 2018)
 - Viewflow 1.2.x compatible with Django 1.11/2.0 (supported till Django 1.11 lifetime/April 2020)
 - Viewflow 1.3.x/1.4.x/1.5.x compatible with Django 1.11/2.0/2.1/2.2 (supported till Django 1.11 lifetime/April 2020)
-- Viewflow 1.6.x compatible with Django 2.0/2.1/2.2/3.0/3.1
+- Viewflow 1.6.x/1.7.x compatible with Django 2.0/2.1/2.2/3.0/3.1 (supported till Django 2.0 lifetime/December 2020)
+- Viewflow 1.8.x compatible with Django 2.1/2.2/3.0/3.1
 
 Introduction
 ============
@@ -124,7 +125,8 @@ Please see `FAQ <https://github.com/kmmbvnr/django-viewflow/wiki/Pro-FAQ>`_ for
 Latest changelog
 ================
 
-1.7.0 2020-11-18
+1.8.0 2021-01-07
 ----------------
 
-* Fix TaskQuerySet.user_queue filtering. Remove django 1.8 compatibility code
+* Clean Django 4.0 warnings
+* Allow flow.Handler redifinition with inheritance 

tests/test_flow_signal.py

@@ -33,8 +33,8 @@ def test_signal_ignore_activation(self):
 
 start_test_signal = Signal()
 start_ignorable_test_signal = Signal()
-task_test_signal = Signal(providing_args=["process", "task"])
-ignorable_test_signal = Signal(providing_args=["process", "ignore_me"])
+task_test_signal = Signal()
+ignorable_test_signal = Signal()
 
 
 @flow.flow_start_signal

tests/test_templatetags_base.py

@@ -1,7 +1,7 @@
 import django
 
 from django.db import models
-from django.conf.urls import include, url
+from django.urls import include, re_path
 from django.contrib import admin
 from django.contrib.auth.models import User
 from django.test import TestCase
@@ -109,7 +109,7 @@ class TemplateTagProcessEntity(models.Model):
 
 
 urlpatterns = [
-    url(r'^admin/', admin.site.urls)
+    re_path(r'^admin/', admin.site.urls)
 ]
 
 try:

tests/test_templatetags_viewflow.py

@@ -1,4 +1,4 @@
-from django.conf.urls import include, url
+from django.urls import include, re_path
 from django.contrib.auth.models import User
 from django.http.request import QueryDict
 from django.template import Template, Context
@@ -85,5 +85,5 @@ class TestTemplateTagsFlow(Flow):
 
 
 urlpatterns = [
-    url(r'^test/', include((viewset.FlowViewSet(TestTemplateTagsFlow).urls, 'testtemplatetags'))),
+    re_path(r'^test/', include((viewset.FlowViewSet(TestTemplateTagsFlow).urls, 'testtemplatetags'))),
 ]

tests/test_usecase_inheritance.py

@@ -5,8 +5,12 @@
 
 class BaseFlow(Flow):
     start = flow.StartFunction().Next(this.end)
+    handle = flow.Handler(this.handler_execute)
     end = flow.End()
 
+    def handler_execute(self, activation):
+        raise NotImplementedError
+
 
 class FlowMixin(object):
     notify_admins = flow.Handler(this.send_alert).Next(this.notify_users)
@@ -18,6 +22,9 @@ class ChildFlow(FlowMixin, BaseFlow):
     alert = flow.Function(this.send_alert).Next(this.notify_admins)
     notify_users = FlowMixin.notify_users.Next(this.end)
 
+    def handler_execute(self, activation):
+        raise NotImplementedError
+
     def send_alert(self, activation):
         activation.prepare()
         activation.done()
@@ -27,10 +34,6 @@ class Test(TestCase):
     def test_base_flow_unchanged(self):
         self.assertEqual(BaseFlow.start._next, BaseFlow.end)
 
-    def test_child_flow_got_base_nodes(self):
-        self.assertEqual(ChildFlow.end, BaseFlow.end)
-        self.assertEqual(ChildFlow._meta.node('end'), BaseFlow.end)
-
     def test_child_flow_overides_base_node(self):
         self.assertEqual(ChildFlow.alert._next, ChildFlow.notify_admins)
         self.assertEqual(ChildFlow.notify_users._next, ChildFlow.end)
@@ -43,4 +46,8 @@ def test_child_flow_contains_all_urls(self):
             'notify_admins__perform', 'notify_admins__cancel', 'notify_admins__undo',
             'notify_admins__detail', 'notify_users__perform', 'notify_users__cancel',
             'notify_users__undo', 'notify_users__detail', 'start__perform',
-            'start__cancel', 'start__undo', 'start__detail']))
+            'start__cancel', 'start__undo', 'start__detail',
+            'handle__cancel', 'handle__undo', 'handle__detail', 'handle__perform']))
+
+    def test_handle_proper_initialized(self):
+        self.assertEqual(ChildFlow.handle.handler, ChildFlow.instance.handler_execute)

tests/test_views_actions.py

@@ -1,4 +1,4 @@
-from django.conf.urls import include, url
+from django.urls import include, re_path
 from django.contrib.auth.models import User
 from django.test import TestCase, RequestFactory
 from django.urls import resolve
@@ -251,7 +251,7 @@ class ActionsTestFlow(Flow):
 
 
 urlpatterns = [
-    url(r'^test/', include((viewset.FlowViewSet(ActionsTestFlow).urls, 'actionstest')))
+    re_path(r'^test/', include((viewset.FlowViewSet(ActionsTestFlow).urls, 'actionstest')))
 ]
 
 try:

tests/test_views_base.py

@@ -1,4 +1,4 @@
-from django.conf.urls import include, url
+from django.urls import include, re_path
 from django.contrib.auth.models import User
 from django.test import TestCase, RequestFactory
 from django.urls import resolve
@@ -97,7 +97,7 @@ class BaseViewTestFlow(Flow):
 
 
 urlpatterns = [
-    url(r'^test/', include((viewset.FlowViewSet(BaseViewTestFlow).urls, 'baseviewtest')))
+    re_path(r'^test/', include((viewset.FlowViewSet(BaseViewTestFlow).urls, 'baseviewtest')))
 ]
 
 try:

tests/test_views_list.py

@@ -1,4 +1,4 @@
-from django.conf.urls import include, url
+from django.urls import include, re_path
 from django.contrib.auth.models import User
 from django.test import TestCase, RequestFactory
 from django.urls import resolve
@@ -112,7 +112,7 @@ class ListViewTestFlow(Flow):
 
 
 urlpatterns = [
-    url(r'^test/', include((viewset.FlowViewSet(ListViewTestFlow).urls, 'listviewtest')))
+    re_path(r'^test/', include((viewset.FlowViewSet(ListViewTestFlow).urls, 'listviewtest')))
 ]
 
 try:

tests/test_views_start.py

@@ -1,4 +1,4 @@
-from django.conf.urls import include, url
+from django.conf.urls import include, re_path
 from django.contrib.auth.models import User
 from django.db import models
 from django.test import TestCase, RequestFactory
@@ -77,7 +77,7 @@ class StartViewFlowEntity(models.Model):
 
 
 urlpatterns = [
-    url(r'^test/', include((viewset.FlowViewSet(StartViewTestFlow).urls, 'startviewtest')))
+    re_path(r'^test/', include((viewset.FlowViewSet(StartViewTestFlow).urls, 'startviewtest')))
 ]
 
 try:

tests/test_views_task.py

@@ -1,5 +1,5 @@
 from django.urls import resolve
-from django.conf.urls import include, url
+from django.conf.urls import include, re_path
 from django.db import models
 from django.contrib.auth.models import User
 from django.test import TestCase, RequestFactory
@@ -142,7 +142,7 @@ class TaskViewFlowEntity(models.Model):
 
 
 urlpatterns = [
-    url(r'^test/', include((viewset.FlowViewSet(TaskViewTestFlow).urls, 'taskviewtest')))
+    re_path(r'^test/', include((viewset.FlowViewSet(TaskViewTestFlow).urls, 'taskviewtest')))
 ]
 
 try:

tox.ini

@@ -1,7 +1,7 @@
 [tox]
 envlist =
-    py{36}-{dj20,dj21,dj22}
-    py{37}-{dj20,dj21,dj22,dj30,dj31}
+    py{36}-{dj22}
+    py{37}-{dj22,dj30,dj31}
     py{38}-{dj30,dj31}
 skipsdist = True
 
@@ -35,8 +35,6 @@ basepython =
     py37: python3.7
     py38: python3.8
 deps =
-    dj20: Django==2.0.13
-    dj21: Django==2.1.15
     dj22: Django==2.2.17
     dj30: Django==3.0.11
     dj31: Django==3.1.3

viewflow/base.py

@@ -4,6 +4,7 @@
 from __future__ import unicode_literals
 
 import re
+from copy import copy
 from collections import defaultdict
 from textwrap import dedent
 from six import with_metaclass
@@ -23,7 +24,7 @@ def __init__(self, nodes):  # noqa
 
     def get_implementation(self, link):
         if isinstance(link, Node):
-            return link
+            return self.nodes.get(link.name)
         elif isinstance(link, ThisObject):
             node = self.nodes.get(link.name)
             if not node:
@@ -102,19 +103,24 @@ class FlowMetaClass(type):
 
     def __new__(cls, class_name, bases, attrs):
         """Construct new flow class."""
-        new_class = super(FlowMetaClass, cls).__new__(cls, class_name, bases, attrs)
-
-        # singleton instance
-        new_class.instance = FlowInstanceDescriptor()
-
         # set up flow tasks
         nodes = {}
+
         for base_class in bases:
             for name, attr in base_class.__dict__.items():
                 if isinstance(attr, Node):
-                    nodes[name] = attr
-        nodes.update({name: attr for name, attr in attrs.items()
-                      if isinstance(attr, Node)})
+                    nodes[name] = copy(attr)
+
+        for name, attr in attrs.items():
+            if isinstance(attr, Node):
+                nodes[name] = copy(attr)
+
+        attrs.update(nodes)
+
+        new_class = super(FlowMetaClass, cls).__new__(cls, class_name, bases, attrs)
+
+        # singleton instance
+        new_class.instance = FlowInstanceDescriptor()
 
         for name, node in nodes.items():
             node.name = name

viewflow/nodes/func.py

@@ -137,16 +137,20 @@ class MyFlow(Flow):
              MyFlow.shipment_received_handler.run(task=task)
 
         """
-        self.func = func
-        self.task_loader = task_loader
+        self._func = func
+        self._task_loader = task_loader
         super(Function, self).__init__(**kwargs)
 
     def ready(self):
         """Resolve internal `this`-references."""
-        if isinstance(self.func, ThisObject):
-            self.func = getattr(self.flow_class.instance, self.func.name)
-        if isinstance(self.task_loader, ThisObject):
-            self.task_loader = getattr(self.flow_class.instance, self.task_loader.name)
+        if isinstance(self._func, ThisObject):
+            self.func = getattr(self.flow_class.instance, self._func.name)
+        else:
+            self.func = self._func
+        if isinstance(self._task_loader, ThisObject):
+            self._task_loader = getattr(self.flow_class.instance, self._task_loader.name)
+        else:
+            self.task_loader = self._task_loader
 
     def run(self, *args, **kwargs):
         """Execute the function task."""

viewflow/nodes/handler.py

@@ -100,10 +100,12 @@ def calc_order_total(self, activation):
     activation_class = HandlerActivation
 
     def __init__(self, handler, **kwargs):  # noqa D102
-        self.handler = handler
+        self._handler = handler
         super(Handler, self).__init__(**kwargs)
 
     def ready(self):
         """Resolve internal `this`-references."""
-        if isinstance(self.handler, ThisObject):
-            self.handler = getattr(self.flow_class.instance, self.handler.name)
+        if isinstance(self._handler, ThisObject):
+            self.handler = getattr(self.flow_class.instance, self._handler.name)
+        else:
+            self.handler = self._handler