Inserter section

An inserter pipeline section lets you define a key and value to insert into pipeline items. The inserter section blueprint name is collective.transmogrifier.sections.inserter.

A inserter section takes a key and a value TALES expression. These expressions are evaluated to generate the actual key-value pair that gets inserted. You can also specify an optional condition option; if given, the key only gets inserted when the condition, which is also a TALES is true.

Because the inserter value expression has access to the original item, it could even be used to change existing item values. Just target an existing key, pull out the original value in the value expression and return a modified version.

>>> inserter = """
... [transmogrifier]
... pipeline =
...     source
...     simple-insertion
...     expression-insertion
...     transform-id
...     logger
...
... [source]
... blueprint = collective.transmogrifier.sections.tests.rangesource
... size = 3
...
... [simple-insertion]
... blueprint = collective.transmogrifier.sections.inserter
... key = string:foo
... value = string:bar (inserted into "${item/id}" by the "$name" section)
...
... [expression-insertion]
... blueprint = collective.transmogrifier.sections.inserter
... key = python:'foo-%s' % item['id'][-2:]
... value = python:int(item['id'][-2:]) * 15
... condition = python:int(item['id'][-2:])
...
... [transform-id]
... blueprint = collective.transmogrifier.sections.inserter
... key = string:id
... value = string:foo-${item/id}
...
... [logger]
... blueprint = collective.transmogrifier.sections.logger
... name = logger
... level = INFO
... """
>>> registerConfig(u'collective.transmogrifier.sections.tests.inserter',
...                inserter)
>>> transmogrifier(u'collective.transmogrifier.sections.tests.inserter')
>>> print handler
logger INFO
    {'foo': 'bar (inserted into "item-00" by the "simple-insertion" section)',
    'id': 'foo-item-00'}
logger INFO
    {'foo': 'bar (inserted into "item-01" by the "simple-insertion" section)',
    'foo-01': 15,
    'id': 'foo-item-01'}
logger INFO
    {'foo': 'bar (inserted into "item-02" by the "simple-insertion" section)',
    'foo-02': 30,
    'id': 'foo-item-02'}

The key, value and condition expressions have access to the following:

item	the current pipeline item
transmogrifier	the transmogrifier
name	the name of the inserter section
options	the inserter options
modules	sys.modules
key	(only for the value and condition expressions) the key being inserted