Writer section
==============

A writer pipeline section is used to store files in different GenericSetup
export contexts. The writer section blueprint name is 
``quintagroup.transmogrifier.writer``.

>>> writer = """
... [transmogrifier]
... pipeline =
...     writersource
...     writer
...     dataprinter
...     
... [writersource]
... blueprint = quintagroup.transmogrifier.tests.writersource
... 
... [writer]
... blueprint = quintagroup.transmogrifier.writer
... prefix = structure
... 
... [dataprinter]
... blueprint = quintagroup.transmogrifier.tests.dataprinter
... prettyprint = true
... print = 
...     _export_context
...     _wrote
... """
>>> registerConfig(u'quintagroup.transmogrifier.tests.writer', writer)
>>> transmogrifier(u'quintagroup.transmogrifier.tests.writer') # doctest: +ELLIPSIS, +REPORT_NDIFF
[('structure/spam/eggs/foo/.second.xml', 'other data', 'text/xml'),
 ('structure/spam/eggs/foo/.first.xml', 'some data', 'text/xml')]
[('structure/spam/eggs/foo/.second.xml', 'other data', 'text/xml'),
 ('structure/spam/eggs/foo/.first.xml', 'some data', 'text/xml'),
 ('structure/other/path/.third.xml', 'some data', 'text/xml')]

Now we test if writer context is properly controlled by ``context`` option.

>>> writerdefault = """
... [transmogrifier]
... pipeline =
...     source
...     writer
...     printer
...     
... [source]
... blueprint = quintagroup.transmogrifier.tests.singleitemsource
... 
... [writer]
... blueprint = quintagroup.transmogrifier.writer
... 
... [printer]
... blueprint = collective.transmogrifier.sections.tests.pprinter
... """
>>> registerConfig(u'quintagroup.transmogrifier.tests.writerdefault', writerdefault)
>>> transmogrifier(u'quintagroup.transmogrifier.tests.writerdefault') # doctest: +ELLIPSIS, +REPORT_NDIFF
{'_export_context': <Tarball args=(...) _wrote=[]>,
 '_files': {},
 '_path': ''}
>>> writerdir = """
... [transmogrifier]
... include = quintagroup.transmogrifier.tests.writerdefault
... 
... [writer]
... context = directory
... path = content
... """
>>> registerConfig(u'quintagroup.transmogrifier.tests.writerdir', writerdir)
>>> transmogrifier(u'quintagroup.transmogrifier.tests.writerdir') # doctest: +ELLIPSIS, +REPORT_NDIFF
{'_export_context': <Directory args=(..., 'content') _wrote=[]>,
 '_files': {},
 '_path': ''}
>>> writertar = """
... [transmogrifier]
... include = quintagroup.transmogrifier.tests.writerdefault
...
... [writer]
... context = tarball
... """
>>> registerConfig(u'quintagroup.transmogrifier.tests.writertar', writertar)
>>> transmogrifier(u'quintagroup.transmogrifier.tests.writertar') # doctest: +ELLIPSIS, +REPORT_NDIFF
{'_export_context': <Tarball args=(...) _wrote=[]>,
 '_files': {},
 '_path': ''}
>>> writerdb = """
... [transmogrifier]
... include = quintagroup.transmogrifier.tests.writerdefault
...
... [writer]
... context = snapshot
... """
>>> registerConfig(u'quintagroup.transmogrifier.tests.writerdb', writerdb)
>>> transmogrifier(u'quintagroup.transmogrifier.tests.writerdb') # doctest: +ELLIPSIS, +REPORT_NDIFF
{'_export_context': <Snapshot args=(..., 'snapshot-...') _wrote=[]>,
 '_files': {},
 '_path': ''}