[Zope-dev] Problems with allow_class and class built-in __dict__

[Manuel Markwort]

hello,

today i ran into a problem with zope.
i've wrote some base-classes in c++, using Boost.Python (www.boost.org) to export them into a
python-module. the module (.pyd-file) works fine with my python-interpreter (v2.3.3). i can import
it, instanciate objects of my c++-classes and use their methods successfully.

my module is aimed to extend one of my zope-products. in the current level of development, the module
contains a first bunch of classes, which provide the basic functionality. so, i wanted to test my module
not only with the commandline-interpreter of python, but in zope, as well.
my setup runs zope v2.7.1 (win32, with python v2.3.3), which worked fine until today.

i've started to write a new zope-product, making my module useable in zope. in the 
initializer-script i tried to allow my module and the classes in it on the usual way:


<-- start: __init__.py -->

from Products.PythonScripts.Utility import allow_module, allow_class

allow_module("Products.ABPcWeb")
allow_module("Products.ABPcWeb.ssl2du") <-- THE PYD FILE
allow_class(PySslSet)		<-
allow_class(PySslEntry)		 | Classes in ssl2du.pyd
allow_class(PyAccessSsl)	 |
allow_class(PySslStatement)	<-

__version__		= "0.01"
__product_name__	= "ABPcWeb"

def initialize(context):
    pass

<-- end: __init__.py -->


the product is called 'ABPcWeb', and my .pyd 'ssl2du'. looks ok, i thought, but zope throws this
error on startup:


<-- start: zope-error -->

Loading ABPcWeb ...
------
2004-11-05T16:14:58 ERROR(200) Zope Could not import Products.ABPcWeb
Traceback (most recent call last):
  File "C:\Program Files\Zope-2.7.1\lib\python\OFS\Application.py", line 660, in import_product
    product=__import__(pname, global_dict, global_dict, silly)
  File "C:\Zope-Instance\Products\ABPcWeb\__init__.py", line 8, in ?
    allow_class(PySslSet)
  File "C:\Program Files\Zope-2.7.1\lib\python\AccessControl\SecurityInfo.py", line 313, in allow_class
    sec.apply(Class)
  File "C:\Program Files\Zope-2.7.1\lib\python\AccessControl\SecurityInfo.py", line 165, in apply
    dict['%s__roles__' % name] = access
TypeError: object does not support item assignment
Traceback (most recent call last):
  File "C:\Program Files\Zope-2.7.1\lib\python\Zope\Startup\run.py", line 50, in ?
    run()
  File "C:\Program Files\Zope-2.7.1\lib\python\Zope\Startup\run.py", line 19, in run
    start_zope(opts.configroot)
  File "C:\Program Files\Zope-2.7.1\lib\python\Zope\Startup\__init__.py", line 51, in start_zope
    starter.startZope()
  File "C:\Program Files\Zope-2.7.1\lib\python\Zope\Startup\__init__.py", line 230, in startZope
    Zope.startup()
  File "C:\Program Files\Zope-2.7.1\lib\python\Zope\__init__.py", line 47, in startup
    _startup()
  File "C:\Program Files\Zope-2.7.1\lib\python\Zope\App\startup.py", line 45, in startup
    OFS.Application.import_products()
  File "C:\Program Files\Zope-2.7.1\lib\python\OFS\Application.py", line 637, in import_products
    import_product(product_dir, product_name, raise_exc=debug_mode)
  File "C:\Program Files\Zope-2.7.1\lib\python\OFS\Application.py", line 660, in import_product
    product=__import__(pname, global_dict, global_dict, silly)
  File "C:\Zope-Instance\Products\ABPcWeb\__init__.py", line 8, in ?
    allow_class(PySslSet)
  File "C:\Program Files\Zope-2.7.1\lib\python\AccessControl\SecurityInfo.py", line 313, in allow_class
    sec.apply(Class)
  File "C:\Program Files\Zope-2.7.1\lib\python\AccessControl\SecurityInfo.py", line 165, in apply
    dict['%s__roles__' % name] = access
TypeError: object does not support item assignment

<-- end: zope-error -->


after searching the web for a possible solution of that problem, i realized that since python v2.2
the __dict__-attribute isnt a real dictionary, but a proxy-object. a direct access to __dict__ isnt
allowed anymore, so zope cant do its work.

to solve the problem, i've patched the following two files:
<Zope-Root>/lib/python/AccessControl/SecurityInfo.py
and
<Zope-Root>/lib/python/App/class_init.py

i've changed all direct-access commands invoking __dict__ to setattr()- and delattr()-methods.
for example:

--(SecurityInfo.py Line: 165)-- 
dict['%s__roles__' % name] = access

now is:

setattr(classobj, ('%s__roles__' % name), access)

after that changes, the allowing of my module + classes worked well.

now my question:
is there a workaround for that problem without changing the zope-source ? is that 'bug' fixed in
further versions ?


best regards,
Manuel Markwort