[Zope3-Users] Re: User preferences for languages- possible?

[Philipp von Weitershausen]

Giovannetti, Mark wrote:
> Hi,
> 
> This stuff is crazy.  I just want to implement a user
> preference for a language (because I have to).  I've
> read all the user pref. documentation (skinpref, apidoc
> prefs and zope.app.preference) until I'm blue in the
> face.  Nothing seems to work and there is no help via
> google and so forth.
> 
> I know that UserPreferences() wants an ILocation object.
> I can't seem to get one inside the BrowserFormLanguages
> class.  I am only given the request object.
> 
> What do I need to do?  Getting a root site is insane
> the way I found to do it via a mailing list message.  Not
> to mention it had issues racking up db connections, then
> failing on close.
> 
> Help! Please! Thank you!
> 
> Preferences seem to work since I can edit them using
> the http://.../++preferences++/ form.

The zope.app.preference stuff stores the info in principal annotations, 
in a weird way. I personally find that stuff a bit convoluted.

The key, as you've correctly identified, is write your own 
IUserPreferredLanguages adapter (or a variant thereof). I would store 
the user's preferences in a cookie or a session. This makes things much 
easier. Simply adapt the request to ISession(request).

Note that this might not always work, e.g. when the request is 
instantiated and the request's locale is first created (because local 
utilities to store the session data in aren't available at that point). 
It seems you're hitting that exact problem with the preference stuff as 
well. The trick here is to stub this out when the adapter is first 
called, and then later during traversal, when you know the local 
components are there, you revisit it all again by calling 
request.setUpLocale() or whatever it is. The ++lang++ implementation 
might give some pointers.


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