Problem overriding IUserPreferredLanguages

Hello,

First of all, note that is my very first forry into Five/Zope 3 ... (Though
I know 2.7 well!) I'm using 2.9.2 right now.

I'm trying to use my own system of determining the language to use, based on
the URL.

Using Five/i18n.py and http://codespeak.net/z3/five/i18n.html, I've created
a very small product to start with:

i18n.py:

from zope.interface import implements
from zope.i18n.interfaces import IUserPreferredLanguages

class PathLanguages(object):
    implements(IUserPreferredLanguages)

    def __init__(self, context):
        self.context = context

    def getPreferredLanguages(self):
        request = self.context
        stack = request['TraversalRequestNameStack']
        if stack and len(stack) > 0 and stack[-1] in ['en', 'fr']:
            # A language entry is in the path
            lang = stack.pop(-1)
            # Rewrite the path so all links will have the language path
entry
            base_parts = request['VIRTUAL_URL_PARTS'][1]
            request.setVirtualRoot([base_parts] + [lang])
            return [lang]
        else:
            return ['en']

And overrides.zcml:

<configure xmlns="http://namespaces.zope.org/zope";
           xmlns:i18n="http://namespaces.zope.org/i18n";
           xmlns:five="http://namespaces.zope.org/five";>

  <adapter for="zope.publisher.interfaces.http.IHTTPRequest"
           provides="zope.i18n.interfaces.IUserPreferredLanguages"
           factory=".i18n.PathLanguages" />

</configure>

But this seems to do absolutely nothing :(

I've tried adding raises or prints in the code and so on, but as best I can
tell, it never gets called.  The __init__ for the Product is empty.

Basically, it's my first Five product, and it's only supposed to set the
language, but I can't even get it to do that.

Anyone care to point me in the right direction?

Thanks in advance for the help ...

Jean-François Doyon
Internet Service Development and Systems Support / Spécialiste de
dèveloppements internet et soutien technique
Canada Centre for Remote Sensing/Centre Canadien de télédétection
Natural Resources Canada/Ressources Naturelles Canada
http://atlas.gc.ca
Tel./Tél.: (613) 992-4902
Fax: (613) 947-2410