- In ``bfg_routesalchemy``, ``bfg_alchemy`` and ``bfgwiki2`` tutorial,

  clean up the SQLAlchemy connection by registering a
  ``repoze.tm.after_end`` callback instead of relying on a ``__del__``
  method of a ``Cleanup`` class added to the WSFI environment.  The
  ``__del__`` strategy was fragile and caused problems in the wild.
  Thanks to Daniel Holth for testing.

1 files changed, 9 insertions, 9 deletions

diff --git a/docs/tutorials/bfgwiki2/src/authorization/tutorial/run.py b/docs/tutorials/bfgwiki2/src/authorization/tutorial/run.py
index 2506ca939..2e38bd29b 100644
--- a/docs/tutorials/bfgwiki2/src/authorization/tutorial/run.py
+++ b/docs/tutorials/bfgwiki2/src/authorization/tutorial/run.py
@@ -1,18 +1,18 @@
+import transaction
+
 from repoze.bfg.configuration import Configurator
+from repoze.tm import after_end
+from repoze.tm import isActive
 
 from tutorial.models import DBSession
 from tutorial.models import initialize_sql
 from tutorial.models import RootFactory
 
-class Cleanup:
-    def __init__(self, cleaner):
-        self.cleaner = cleaner
-    def __del__(self):
-        self.cleaner()
-
 def handle_teardown(event):
     environ = event.request.environ
-    environ['tutorial.sasession'] = Cleanup(DBSession.remove)
+    if isActive(environ):
+        t = transaction.get()
+        after_end.register(DBSession.remove, t)
 
 def app(global_config, **settings):
     """ This function returns a WSGI application.
@@ -22,8 +22,8 @@ def app(global_config, **settings):
     """
     db_string = settings.get('db_string')
     if db_string is None:
-        raise ValueError(
-            "No 'db_string' value in application configuration.")
+        raise ValueError("No 'db_string' value in application "
+                         "configuration.")
     initialize_sql(db_string)
     config = Configurator(settings=settings, root_factory=RootFactory)
     config.begin()