[z3-five] can't import an interface into a page template

[Tim Hicks]

I'm trying to get hold of an interface (of the zope3 variety) from a zpt
so that I can adapt to it. So, my zpt has::

  <tal:dummy define="IMessageFlags
modules/Products.atemail.interfaces.IMessageFlags">

However, no matter how I declare security, I cannot manage to import
IMessageFlags.  I have tried the following in the product __init__.py::

  from Products.PythonScripts.Utility import allow_module, allow_class

followed by either::

  allow_module('interfaces')

or::

  allow_module('Products.atemail.interfaces')

The end of the traceback I get when I view the zpt is::

    mod = safe_builtins['__import__'](module)
  File "/home/tim/zope/2.8-pre/lib/python/AccessControl/ZopeGuards.py",
line 281, in guarded_import
    module = load_module(None, None, mnameparts, validate, globals, locals)
  File "/home/tim/zope/2.8-pre/lib/python/AccessControl/ZopeGuards.py",
line 344, in load_module
    if module and not validate(module, module, nextname, nextmodule):
Unauthorized: You are not allowed to access 'interfaces' in this context

When I try::

  allow_class('interfaces.IMessageFlags')

I get the following traceback upon zope startup::

Traceback (most recent call last):
  File "/home/tim/zope/2.8-pre/lib/python/Zope/Startup/run.py", line 56, in ?
    run()
  File "/home/tim/zope/2.8-pre/lib/python/Zope/Startup/run.py", line 21,
in run
    starter.prepare()
  File "/home/tim/zope/2.8-pre/lib/python/Zope/Startup/__init__.py", line
96, in prepare
    self.startZope()
  File "/home/tim/zope/2.8-pre/lib/python/Zope/Startup/__init__.py", line
252, in startZope
    Zope.startup()
  File "/home/tim/zope/2.8-pre/lib/python/Zope/__init__.py", line 47, in
startup
    _startup()
  File "/home/tim/zope/2.8-pre/lib/python/Zope/App/startup.py", line 46,
in startup
    OFS.Application.import_products()
  File "/home/tim/zope/2.8-pre/lib/python/OFS/Application.py", line 638,
in import_products
    import_product(product_dir, product_name, raise_exc=debug_mode)
  File "/home/tim/zope/2.8-pre/lib/python/OFS/Application.py", line 661,
in import_product
    product=__import__(pname, global_dict, global_dict, silly)
  File "/home/tim/zope/2.8instance/Products/atemail/__init__.py", line 22,
in ?
    allow_class('interfaces.IMessageFlags')
  File "/home/tim/zope/2.8-pre/lib/python/AccessControl/SecurityInfo.py",
line 309, in allow_class
    Class._security = sec = ClassSecurityInfo()
AttributeError: 'str' object has no attribute '_security'


Am I doing something silly (that should be posted on zope at zope.org) or is
there something else wrong?

Alternatively, is there another way around this?

Thanks,

tim