Backward compatible middleware (#403)

* Roll back middleware class so that it supports old style middleware

* More reasonable comment for middleware setting

* Use different middleware styles in tests for Django 2.0 and previous versions

* Roll back middleware class so that it supports old style middleware

* More reasonable comment for middleware setting

* Use different middleware styles in tests for Django 2.0 and previous versions

* Rename variable to fit into line length

Author: iamanikeev

AUTHORS.rst

@@ -59,6 +59,7 @@ Authors
 - Ray Logel
 - Nathan Villagaray-Carski
 - Mike Spainhower
+- Alexander Anikeev
 
 Background
 ==========

CHANGES.rst

@@ -7,6 +7,7 @@ Unreleased
 - Add ability to specify custom history_id field (gh-368)
 - Add HistoricalRecord instance properties `prev_record` and `next_record` (gh-365)
 - Can set admin methods as attributes on object history change list template (gh-390)
+- Fixed compatibility of >= 2.0 versions with old-style middleware (gh-369)
 
 2.0 (2018-04-05)
 ----------------

runtests.py

@@ -39,11 +39,6 @@
             'ENGINE': 'django.db.backends.sqlite3',
         }
     },
-    MIDDLEWARE=[
-        'django.contrib.sessions.middleware.SessionMiddleware',
-        'django.contrib.auth.middleware.AuthenticationMiddleware',
-        'django.contrib.messages.middleware.MessageMiddleware',
-    ],
     TEMPLATES=[{
         'BACKEND': 'django.template.backends.django.DjangoTemplates',
         'APP_DIRS': True,
@@ -54,6 +49,16 @@
         },
     }],
 )
+MIDDLEWARE = [
+    'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.contrib.auth.middleware.AuthenticationMiddleware',
+    'django.contrib.messages.middleware.MessageMiddleware',
+]
+
+if django.__version__ >= '2.0':
+    DEFAULT_SETTINGS['MIDDLEWARE'] = MIDDLEWARE
+else:
+    DEFAULT_SETTINGS['MIDDLEWARE_CLASSES'] = MIDDLEWARE
 
 
 def main():

simple_history/middleware.py

@@ -1,29 +1,20 @@
+from django.utils.deprecation import MiddlewareMixin
+
 from .models import HistoricalRecords
 
 
-class HistoryRequestMiddleware:
+class HistoryRequestMiddleware(MiddlewareMixin):
     """Expose request to HistoricalRecords.
 
     This middleware sets request as a local thread variable, making it
     available to the model-level utilities to allow tracking of the
     authenticated user making a change.
     """
 
-    def __init__(self, get_response):
-        self.get_response = get_response
-
-    def __call__(self, request):
-        # Code to be executed for each request before
-        # the view (and later middleware) are called.
-
+    def process_request(self, request):
         HistoricalRecords.thread.request = request
 
-        response = self.get_response(request)
-
-        # Code to be executed for each request/response after
-        # the view is called.
-
+    def process_response(self, request, response):
         if hasattr(HistoricalRecords.thread, 'request'):
             del HistoricalRecords.thread.request
-
         return response

simple_history/tests/tests/test_admin.py

@@ -1,6 +1,5 @@
 from datetime import datetime, timedelta
 
-from django.conf import settings
 from django.contrib.admin import AdminSite
 from django.contrib.admin.utils import quote
 from django.contrib.auth import get_user_model
@@ -14,6 +13,7 @@
 
 from simple_history.admin import SimpleHistoryAdmin
 from simple_history.models import HistoricalRecords
+from simple_history.tests.tests.utils import middleware_override_settings
 from ..models import (
     Book,
     Choice,
@@ -45,12 +45,6 @@ def get_history_url(obj, history_index=None, site="admin"):
             site=site, app=app, model=model), args=[quote(obj.pk)])
 
 
-overridden_settings = {
-    'MIDDLEWARE': (settings.MIDDLEWARE +
-                   ['simple_history.middleware.HistoryRequestMiddleware']),
-}
-
-
 class AdminSiteTest(WebTest):
     def setUp(self):
         self.user = User.objects.create_superuser('user_login',
@@ -231,7 +225,7 @@ def test_history_user_not_saved(self):
             "No way to know of request, history_user should be unset.",
         )
 
-    @override_settings(**overridden_settings)
+    @override_settings(**middleware_override_settings)
     def test_middleware_saves_user(self):
         self.login()
         form = self.app.get(reverse('admin:tests_book_add')).form
@@ -244,13 +238,13 @@ def test_middleware_saves_user(self):
                          "Middleware should make the request available to "
                          "retrieve history_user.")
 
-    @override_settings(**overridden_settings)
+    @override_settings(**middleware_override_settings)
     def test_middleware_unsets_request(self):
         self.login()
         self.app.get(reverse('admin:tests_book_add'))
         self.assertFalse(hasattr(HistoricalRecords.thread, 'request'))
 
-    @override_settings(**overridden_settings)
+    @override_settings(**middleware_override_settings)
     def test_rolled_back_user_does_not_lead_to_foreign_key_error(self):
         # This test simulates the rollback of a user after a request (which
         # happens, e.g. in test cases), and verifies that subsequently
@@ -270,7 +264,7 @@ def test_rolled_back_user_does_not_lead_to_foreign_key_error(self):
             "No way to know of request, history_user should be unset.",
         )
 
-    @override_settings(**overridden_settings)
+    @override_settings(**middleware_override_settings)
     def test_middleware_anonymous_user(self):
         self.app.get(reverse('admin:index'))
         poll = Poll.objects.create(question="why?", pub_date=today)

simple_history/tests/tests/test_middleware.py

@@ -1,18 +1,14 @@
 from datetime import date
 
-from django.conf import settings
 from django.test import TestCase, override_settings
 from django.urls import reverse
 
 from simple_history.tests.custom_user.models import CustomUser
 from simple_history.tests.models import Poll
-
-overridden_settings = {
-    'MIDDLEWARE': (settings.MIDDLEWARE +
-                   ['simple_history.middleware.HistoryRequestMiddleware']),
-}
+from simple_history.tests.tests.utils import middleware_override_settings
 
 
+@override_settings(**middleware_override_settings)
 class MiddlewareTest(TestCase):
     def setUp(self):
         self.user = CustomUser.objects.create_superuser(
@@ -21,7 +17,6 @@ def setUp(self):
             'pass'
         )
 
-    @override_settings(**overridden_settings)
     def test_user_is_set_on_create_view_when_logged_in(self):
         self.client.force_login(self.user)
         data = {
@@ -37,7 +32,6 @@ def test_user_is_set_on_create_view_when_logged_in(self):
         self.assertListEqual([ph.history_user_id for ph in poll_history],
                              [self.user.id])
 
-    @override_settings(**overridden_settings)
     def test_user_is_not_set_on_create_view_not_logged_in(self):
         data = {
             'question': 'Test question',
@@ -52,7 +46,6 @@ def test_user_is_not_set_on_create_view_not_logged_in(self):
         self.assertListEqual([ph.history_user_id for ph in poll_history],
                              [None])
 
-    @override_settings(**overridden_settings)
     def test_user_is_set_on_update_view_when_logged_in(self):
         self.client.force_login(self.user)
         poll = Poll.objects.create(
@@ -76,7 +69,6 @@ def test_user_is_set_on_update_view_when_logged_in(self):
         self.assertListEqual([ph.history_user_id for ph in poll_history],
                              [self.user.id, None])
 
-    @override_settings(**overridden_settings)
     def test_user_is_not_set_on_update_view_when_not_logged_in(self):
         poll = Poll.objects.create(
             question='Test question',
@@ -99,7 +91,6 @@ def test_user_is_not_set_on_update_view_when_not_logged_in(self):
         self.assertListEqual([ph.history_user_id for ph in poll_history],
                              [None, None])
 
-    @override_settings(**overridden_settings)
     def test_user_is_unset_on_update_view_after_logging_out(self):
         self.client.force_login(self.user)
         poll = Poll.objects.create(
@@ -137,7 +128,6 @@ def test_user_is_unset_on_update_view_after_logging_out(self):
         self.assertListEqual([ph.history_user_id for ph in poll_history],
                              [None, self.user.id, None])
 
-    @override_settings(**overridden_settings)
     def test_user_is_set_on_delete_view_when_logged_in(self):
         self.client.force_login(self.user)
         poll = Poll.objects.create(
@@ -155,7 +145,6 @@ def test_user_is_set_on_delete_view_when_logged_in(self):
         self.assertListEqual([ph.history_user_id for ph in poll_history],
                              [self.user.id, None])
 
-    @override_settings(**overridden_settings)
     def test_user_is_not_set_on_delete_view_when_not_logged_in(self):
         poll = Poll.objects.create(
             question='Test question',

simple_history/tests/tests/utils.py

@@ -0,0 +1,17 @@
+import django
+from django.conf import settings
+
+request_middleware = 'simple_history.middleware.HistoryRequestMiddleware'
+
+if django.__version__ >= '2.0':
+    middleware_override_settings = {
+        'MIDDLEWARE': (
+            settings.MIDDLEWARE + [request_middleware]
+        )
+    }
+else:
+    middleware_override_settings = {
+        'MIDDLEWARE_CLASSES': (
+            settings.MIDDLEWARE_CLASSES + [request_middleware]
+        )
+    }