Interfaces exporter and importer sections
=========================================

Interfaces exporter and importer sections are used to migrate interfaces for
objects.
The interfaces exporter section blueprint name is
``quintagroup.transmogrifier.interfacesexporter`` and importer section blueprint
name is ``quintagroup.transmogrifier.interfacesimporter``.

Interfaces are represented in XML format. Both sections need relative
path to the object with interfaces and importer also needs XML data for updating
interfaces provided by object.

Both sections has ``path-key`` option which specifies key in item where path to
object is stored (``_path`` is default) and ``files-key`` option that gives
key where XML data will be or is stored. Also there are ``include`` and
``exclude`` options that give global list of interface identifiers to include or
exclude on serializing. There are correspondent ``include-key``, ``exclude-key``
options, that specifies key where same lists per item is stored (default is
``_included_interfaces`` & ``_excluded_interfaces``). These options give you
alternative way to manage interfaces to serialize and apply to the object.
``include`` option - include only interfaces, listed in, and ``exclude`` option
behave in opposite way. If both options present - only ``include`` option get
into consideration. If both options is absent - all interfaces will be
serialized and/or migrated.
Exporter section exports only Interfaces directly provided by object, so in such
way we prevent confusion with interfaces, implemented by class itself.

>>> import pprint
>>> interfacemanager = """
... [transmogrifier]
... pipeline =
...     interfacemanagersource
...     interfacesexporter
...     printer
...     dataprinter
...     interfacesimporter
...     
... [interfacemanagersource]
... blueprint = quintagroup.transmogrifier.tests.interfacemanagersource
... 
... [interfacesexporter]
... blueprint = quintagroup.transmogrifier.interfacesexporter
... 
... [printer]
... blueprint = collective.transmogrifier.sections.tests.pprinter
... 
... [dataprinter]
... blueprint = quintagroup.transmogrifier.tests.dataprinter
... print = 
...     _files
...     interfaces
...     data
... 
... [interfacesimporter]
... blueprint = quintagroup.transmogrifier.interfacesimporter
... include =
...     zope.annotation.interfaces.IAttributeAnnotatable
... """
>>> registerConfig(u'quintagroup.transmogrifier.tests.interfacemanager', interfacemanager)
>>> transmogrifier(u'quintagroup.transmogrifier.tests.interfacemanager') # doctest: +ELLIPSIS, +REPORT_NDIFF
{}
{'_path': 'not/existing/bar'}
{'_path': 'spam/eggs/notatcontent'}
{'_files': {'interfaces': {'data': ...
                           'name': '.interfaces.xml'}},
 '_path': 'spam/eggs/foo'}
<?xml version="1.0" encoding="utf-8"?>
<interfaces>
  <record>
    zope.annotation.interfaces.IAttributeAnnotatable
  </record>
  <record>
    zope.interface.Interface
  </record>
</interfaces>
<BLANKLINE>

>>> pprint.pprint(updated)
['zope.annotation.interfaces.IAttributeAnnotatable']