[Twisted-Python] nevow.compy.CannotAdapt: WovenContext...

[Mohamed Lrhazi]

I copied some code from an existing site of mine to a new machine and
boom.... does not work anymore :) the code is based on the guard
example... I actually went on to remove more and more of my code till I
realized that even with the basic example itself it fails after the user
logged in :

It seems the code that fails is:

def render_sessionId(self, context, data):
		sess = inevow.ISession(context)
		return context.tag[sess.uid]

The complete trace follows. Any ideas? I probably forget to install
something... did I?

this is gentoo standard ebuilds for python, twisted and nevow:


2005/01/04 16:31 EST [HTTPChannel,0,127.0.0.1] Traceback (most recent
call last):
          File
"/usr/lib/python2.3/site-packages/twisted/protocols/http.py", line 557,
in requestReceived
            self.process()
          File "/usr/lib/python2.3/site-packages/nevow/appserver.py",
line 129, in process
            return self.site.getResourceFor(
          File
"/usr/lib/python2.3/site-packages/twisted/internet/defer.py", line 214,
in addCallback
            callbackKeywords=kw)
          File
"/usr/lib/python2.3/site-packages/twisted/internet/defer.py", line 205,
in addCallbacks
            self._runCallbacks()
        --- <exception caught here> ---
          File
"/usr/lib/python2.3/site-packages/twisted/internet/defer.py", line 338,
in _runCallbacks
            self.result = callback(self.result, *args, **kw)
          File "/usr/lib/python2.3/site-packages/nevow/appserver.py",
line 132, in <lambda>
            lambda resource: inevow.IResource(resource).renderHTTP(self)
          File "/usr/lib/python2.3/site-packages/nevow/rend.py", line
363, in renderHTTP
            return self.flattenFactory(doc, ctx, writer, finisher)
          File "/usr/lib/python2.3/site-packages/nevow/rend.py", line
227, in deferFlattenFactory
            return deferflatten(stan, ctx, writer).addCallback(finisher)
          File "/usr/lib/python2.3/site-packages/nevow/rend.py", line
223, in deferflatten
            drive()
          File "/usr/lib/python2.3/site-packages/nevow/rend.py", line
207, in drive
            deferred, returner = iterable.next()
          File "/usr/lib/python2.3/site-packages/nevow/flat/ten.py",
line 71, in iterflatten
            for item in gen:
          File
"/usr/lib/python2.3/site-packages/nevow/flat/flatstan.py", line 89, in
TagSerializer
            yield serialize(toBeRenderedBy,context)
          File "/usr/lib/python2.3/site-packages/nevow/flat/ten.py",
line 53, in serialize
            return serializer(obj, context)
          File
"/usr/lib/python2.3/site-packages/nevow/flat/flatstan.py", line 215, in
DirectiveSerializer
            return serialize(renderer, context)
          File "/usr/lib/python2.3/site-packages/nevow/flat/ten.py",
line 53, in serialize
            return serializer(obj, context)
          File
"/usr/lib/python2.3/site-packages/nevow/flat/flatstan.py", line 199, in
MethodSerializer
            return FunctionSerializer(original, context, nocontext)
          File
"/usr/lib/python2.3/site-packages/nevow/flat/flatstan.py", line 184, in
FunctionSerializer
            result = original(context, data)
          File "<string>", line 209, in render_sessionId

          File "/usr/lib/python2.3/site-packages/nevow/compy.py", line
73, in __call__
            raise CannotAdapt("%s (type %s) cannot be adapted to %s." %
        nevow.compy.CannotAdapt: WovenContext(tag=Tag('',
specials={'render': Unset}, children=[''])) (type
nevow.context.WovenContext) cannot be adapted to <class
'nevow.inevow.ISession'>.