[Zope-dev] traversal: different with and without a request

[Philipp von Weitershausen]

Dieter Maurer wrote:
> Christian Theune wrote at 2008-10-15 17:42 +0200:
>> we stumbled over an annoyance that took a while to debug:
>>
>> Writing an ITraversable, we used zope.traversing.api.traverse() in a
>> test to verify our code. We registered the ITraversable as an
>> (non-multi) adapter and ended up with a working test.
>>
>> In the actual system, we found that the traversable would not be used.
>> After investigation we found a conditional branch in the traverse()
>> function which would look for a multi-adapter if a request was around,
>> and a regular adapter if not.
>>
>> We didn't anticipate this difference and it cost us some time, so we
>> wonder whether this has to be the way it is, or whether this could be
>> changed to behave more obvious and consistent.
> 
> The request may have important information to control traversal, e.g.
> a layer. On the other hand, when no request is available (e.g. in a
> script), you cannot use one. Thus, the current behaviour may cover
> useful use cases.

True. The request (=layer) is indeed necessary to resolve paths in the 
++view++ aka @@ namespace.