Site walker source section
==========================

A Plone site walker source pipeline section lets you create pipeline items from
contents of Plone site folders. The site walker source section blueprint name is
``quitagroup.transmogrifier.sitewalker``.

A site walker source section will recurse through site's content tree, starting 
form folder, which is the context of transmogrifier, and will yield an item for
each content object. For folder it will also add a tuple of (id, portal_type)
pairs of contained items.

You can also specify an optional ``condition`` option; if given, content object
is going into pipeline only if the condition, which is also a TALES is true.

>>> sitewalker = """
... [transmogrifier]
... pipeline =
...     sitewalker
...     printer
...
... [sitewalker]
... blueprint = quintagroup.transmogrifier.sitewalker
... condition = python:context.getPortalTypeName() not in ('File', 'Image')
...
... [printer]
... blueprint = collective.transmogrifier.sections.tests.pprinter
... """
>>> registerConfig(u'quintagroup.transmogrifier.tests.sitewalker',
...                sitewalker)
>>> transmogrifier(u'quintagroup.transmogrifier.tests.sitewalker')
{'_entries': (('document1', 'Document'),
              ('folder1', 'Folder'),
              ('document3', 'Document')),
 '_path': '',
 '_type': 'MockPortal'}
{'_type': 'Document', '_path': 'document1'}
{'_entries': (('folder2', 'Folder'), ('document2', 'Document')),
 '_path': 'folder1',
 '_type': 'Folder'}
{'_type': 'Folder', '_path': 'folder1/folder2'}
{'_type': 'Document', '_path': 'folder1/document2'}
{'_type': 'Document', '_path': 'document3'}


The ``condition`` expression has an access to the following:

=================== ==========================================================
 ``context``         the current content object
 ``transmogrifier``  the transmogrifier
 ``name``            the name of the splitter section
 ``options``         the splitter options
 ``modules``         sys.modules
=================== ==========================================================