pyramid_traversalwrapper

An alternate implementation of the pyramid.interfaces.ITraverserFactory (a “traverser”) which wraps each traversed object in a proxy. This allows a “location-ignorant” model (a model which does not possess intrinsic __name__ and __parent__ attributes) to be used as the root object and as any object returned from any other model’s __getitem__ method during traversal.

Installation

Install using setuptools, e.g. (within a virtualenv):

$ easy_install pyramid_traversalwrapper

Usage

When this ITraverserFactory is registered as the traverser for a Pyramid application, during traversal, each object, including the root object is wrapped in a proxy. The proxy that provides the traversed object with a __name__ and __parent__ attribute. The __name__ and __parent__ attributes of the root proxy are both None. The __name__ of subsequently traversed object is the Unicode URL segment name which was used to look it up. The __parent__ of subsequently traversed objects is the previous object traversed.

In order to enable this package’s ITraverserFactory, register the pyramid_traversalwrapper.ModelGraphTraverser as the traversal policy, rather than the default ModelGraphTraverser. To use this feature, your application will need to have a dependency on this package. You’ll either need to configure it into your application using the following ZCML stanza:

<adapter
    factory="pyramid_traversalwrapper.ModelGraphTraverser"
    provides="pyramid.interfaces.ITraverserFactory"
    for="*"
    />

Or you can configure it imperatively:

from pyramid.interfaces import ITraverser
from zope.interface import Interface
from pyramid_traversalwrapper import ModelGraphTraverser

config.registry.registerAdapter(ModelGraphTraverser, (Interface,),
                                ITraverser)

Note

When this ITraverserFactory is used, the intrinsic __name__ or __parent__ attribute of an object are ignored. Even if an object in the graph (including the root objects) has an intrinsic __name__ and __parent__ attribute, it will still be wrapped in a proxy that override the object’s “real” __parent__ and __name__ attributes.

Reporting Bugs / Development Versions

Visit https://github.com/Pylons/pyramid_traversalwrapper/issues to report bugs. Visit https://github.com/Pylons/pyramid_traversalwrapper to download development or tagged versions.

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