[storm] storm.zope in a minimal zope CA environment

[Sean Upton]

I'm writing applications in minimal zope component architecture
environment, and I'd like to use storm.zope.  To date, this is not
possible, but only for cosmetic reasons (likely optional
dependencies).  I am using zope.component, zope.event, zope.schema,
and the newly liberated transaction package from PYPI.  I am NOT using
ZODB nor zope.app.* packages (thus not zope.security).  I've made
local changes to work around these limitations.  All tests pass for my
changes, with some modification to the storm.zope doctest README.txt.

Changes I found necessary:
1. Fallback to importing TransactionFailedError in zstorm.py from
transaction if import from ZODB fails.  This works with recent (<3mo.)
transaction in svn and pypi.  This is a second choice, so it should
not interfere with previous deployments of earlier ZODB versions.

2. Optionally import zope.security proxy stuff in __init__.py.

3. Make zope.security proxy doctest stuff optional, dependent on
whether zope.security can be imported.

I plan to create a branch in launchpad for my changes, but I would
like some comment/review from the list before I do this (diff pasted
inline below).  Specifically, my changes to the doctests to deal with
possibly optional dependencies and conditional imports needs
review/thought.

bzr diff output is below my sig...

Any comments/ideas appreciated. Thanks,
Sean Upton
sdupton at gmail.com
sean.upton at uniontrib.com

bzr diff:

=== modified file 'storm/zope/__init__.py'
--- storm/zope/__init__.py      2007-09-19 15:59:35 +0000
+++ storm/zope/__init__.py      2008-02-12 20:21:40 +0000
@@ -19,7 +19,11 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 from zope.interface import classImplements
-from zope.security.checker import NoProxy, BasicTypes, _available_by_default
+try:
+    from zope.security.checker import NoProxy, BasicTypes,
_available_by_default
+    ZOPE_SECURITY = True
+except ImportError:
+    ZOPE_SECURITY = False

 from storm.info import ObjectInfo
 from storm.zope.interfaces import ISQLObjectResultSet
@@ -30,6 +34,7 @@
 # the object info set already).  With this, Storm is able to
 # gracefully handle situations when a proxied object is passed to a
 # Store.
-_available_by_default.append("__storm_object_info__")
-BasicTypes[ObjectInfo] = NoProxy
+if ZOPE_SECURITY:
+    _available_by_default.append("__storm_object_info__")
+    BasicTypes[ObjectInfo] = NoProxy
 classImplements(storm_sqlobject.SQLObjectResultSet, ISQLObjectResultSet)

=== modified file 'storm/zope/zstorm.py'
--- storm/zope/zstorm.py        2007-11-01 16:21:46 +0000
+++ storm/zope/zstorm.py        2008-02-12 20:29:40 +0000
@@ -32,7 +32,11 @@

 import transaction
 from transaction.interfaces import IDataManager, ISynchronizer
-from ZODB.POSException import TransactionFailedError
+try:
+    from ZODB.POSException import TransactionFailedError
+except ImportError:
+    # no ZODB: recent transaction alternately provides TransactionFailedError
+    from transaction.interfaces import TransactionFailedError # >svn r81268

 from storm.zope.interfaces import IZStorm, ZStormError
 from storm.database import create_database

=== modified file 'tests/zope/README.txt'
--- tests/zope/README.txt       2007-09-19 15:59:35 +0000
+++ tests/zope/README.txt       2008-02-13 20:19:05 +0000
@@ -181,14 +181,24 @@
 on Storm-managed objects.

   >>> from storm.info import get_obj_info
-  >>> from zope.security.checker import ProxyFactory
+  >>> try:
+  ...     from zope.security.checker import ProxyFactory
+  ...     ZOPE_SECURITY=True
+  ... except ImportError:
+  ...     ZOPE_SECURITY=False  #tests can pass in a minimal zope environment
+  ...
   >>> from pprint import pprint

   >>> person = store.find(Person).one()
   >>> get_obj_info(person)
   {'store': <...Store object at ...>, 'primary_vars': ...}
-  >>> get_obj_info(ProxyFactory(person))
-  {'store': <...Store object at ...>, 'primary_vars': ...}
+  >>> if ZOPE_SECURITY:
+  ...     value = get_obj_info(ProxyFactory(person))
+  ...     ## get_obj_info() return value equivalent through security proxies:
+  ...     assert type(value['store']) == type(get_obj_info(person)['store'])
+  ...     assert value['store'] == get_obj_info(person)['store']
+  ...     assert value['primary_vars'] == get_obj_info(person)['primary_vars']
+  >>>


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