On Tue, 15 Jul 2008 21:32:39 -0500 Ian Bicking <[EMAIL PROTECTED]> wrote:
> Etienne Robillard wrote: > > > > Hi all, > > > > I'd like to have your input and comments on using decorators > > functions for adding extra options to the request.environ object. > > > > For instance, here's a decorator whichs adds a "scoped" session > > object into request.environ: > > > > def with_session(engine=None): > > """ > > Decorator function for attaching a `Session` instance > > as a keyword argument in `request.environ`. > > """ > > def decorator(view_func): > > def _wrapper(request, *args, **kwargs): > > scoped_session.set_session(engine) > > request.environ['_scoped_session'] = getattr(scoped_session, > > 'sessio > > You should always use a namespace, e.g., > request.environ['something._scoped_session'] = ... > > In the context of a Pylons controller you could do it this way. Of > course with just WSGI it would be better to wrap it via WSGI, which is > almost equivalent to a decorator: > > def with_session(engine=None): > def decorator(app): > def engine_wsgi_app(environ, start_response): > environ['...'] = ... > return app(environ, start_response) > return engine_wsgi_app > return decorator Tried, but its giving me headaches.. I think I will stick with the former... Plus, in webob, it is my assumption that Request objects returns a wsgi application with get_response(). This indicates most likely that both approaches are the same. :) > Pylons controllers aren't *quite* WSGI applications, but instances of > those controller classes are. So wrapping an individual controller with > middleware requires a bit more work. Ah. I just have a conflicting view regarding the definition of a 'middleware'. For me, middlewares shouldn't even exists, as I'm not even sure where they should fit in the WSGI pipeline.. In fact, I consider middlewares as a potential security hole... > > @with_session(engine=engine): > > def view_blog_list(request, *args, **kwargs): > > # get the local session object for this > > # request (thread-local) > > sess = request.environ['_scoped_session'] > > # do stuff with the Session object here... > > ... > > > > Is this a good approach, or can this be adapted to work > > in multithreaded environments ? > > Since you are passing around arguments to functions it should be fine in > threaded environments. Thanks. I'd definitely like to see more discussion regarding threads in the next version of WSGI. > -- > Ian Bicking : [EMAIL PROTECTED] : http://blog.ianbicking.org Kind Regards, Etienne _______________________________________________ Web-SIG mailing list Web-SIG@python.org Web SIG: http://www.python.org/sigs/web-sig Unsubscribe: http://mail.python.org/mailman/options/web-sig/archive%40mail-archive.com
