2fbca9593e
git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@3650 fd906abe-77d9-0310-91a1-e0d9ade77398
120 lines
4.1 KiB
Python
120 lines
4.1 KiB
Python
#
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# Copyright (c) 2009 Helmut Merz helmutm@cy55.de
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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#
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"""
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Interfaces for import/export functionalities.
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$Id$
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"""
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from zope.interface import Attribute, Interface
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class IElement(Interface):
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""" A dicionary-like information element that is able to represent an
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object, a relation between objects or a special attribute.
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The attributes of the object are represented by items of
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the dictionary; the attribute values may be strings, unicode strings,
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or IElement objects.
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"""
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elementType = Attribute('A string denoting the element type.')
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object = Attribute('The object that has been created from this '
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'element during import.')
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parent = Attribute('An optional parent element that this element is part of.')
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subElements = Attribute('An optional list of sub-elements; initially None.')
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def processExport(extractor):
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""" Will be called by the extractor during export to allow for
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special handling e.g. of certain attributes.
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"""
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def add(element):
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""" Add a sub-element, may be called by the extractor during export.
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"""
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def execute(loader):
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""" Create the object that is specified by the element in the
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context of the loader and return it.
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"""
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# import functionality
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class IReader(Interface):
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""" Provides objects in an intermediate format from an external source.
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Will typically be implemented by an utility or an adapter.
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"""
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def read(input):
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""" Retrieve content from the external source returning a sequence
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of IElement objects.
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"""
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class ILoader(Interface):
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""" Inserts data provided by an IReader object into the
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object space of the context object. Will typically be used as an adapter.
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"""
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transcript = Attribute('A string describing the result of the '
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'import process.')
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changes = Attribute('A sequence of mappings describing the '
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'objects that were created or modified by the '
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'import process, together with information about '
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'the changes.')
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errors = Attribute('A sequence of mappings describing the errors '
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'during loading and the corresponding objects.')
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summary = Attribute('A simple mapping giving an overview of the numbers '
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'of newly created and changed objects and the '
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'number of errors.')
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def load(elements):
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""" Create the objects and relations specified by the ``elements``
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argument given.
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"""
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# export functionality
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class IWriter(Interface):
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""" Transforms object information to an external storage.
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"""
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def write(elements):
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""" Write the sequence of elements given in an external format.
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"""
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class IExtractor(Interface):
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""" Extracts information from objects and provides them as
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IElement objects. Will typically be used as an adapter on a
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top-level or root object.
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"""
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count = Attribute('Number of elements extracted.')
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def extract():
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""" Creates and returns a sequence of IElement objects by scanning
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the content of the context object.
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"""
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class ISubExtractor(IExtractor):
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""" Used for extracting special informations from individual objects
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that will be represented by sub-elements.
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"""
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