loops/external/interfaces.py
helmutm 0c4d6dda15 replace Element.__call__() by Element.execute; make PyReader more secure by overwriting __builtins__
git-svn-id: svn://svn.cy55.de/Zope3/src/loops/trunk@2486 fd906abe-77d9-0310-91a1-e0d9ade77398
2008-03-30 08:53:19 +00:00

105 lines
3.4 KiB
Python

#
# Copyright (c) 2008 Helmut Merz helmutm@cy55.de
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
"""
Interfaces for export and import of loops objects.
Maybe part of this stuff should be moved to cybertools.external.
$Id$
"""
from zope.interface import Interface, Attribute
from zope import interface, component, schema
class IElement(Interface):
""" A dicionary-like information element that is able to represent a
loops object, a relation between loops objects or a special attribute.
The attributes of the object are represented by items of
the dictionary; the attribute values may be strings, unicode strings,
or IElement objects.
"""
elementType = Attribute('A string denoting the element type.')
object = Attribute('The object that has been created from this '
'element during import.')
parent = Attribute('An optional parent element that this element is part of.')
subElements = Attribute('An optional list of sub-elements; initially None.')
def processExport(extractor):
""" Will be called by the extractor during export to allow for
special handling e.g. of certain attributes.
"""
def add(element):
""" Add a sub-element, may be called by the extractor during export.
"""
def execute(loader):
""" Create the object that is specified by the element in the
context of the loader and return it.
"""
class IReader(Interface):
""" Provides objects in an intermediate format from an external source.
Will typically be implemented by an utility or an adapter.
"""
def read():
""" Retrieve content from the external source returning a sequence
of IElement objects.
"""
class ILoader(Interface):
""" Inserts data provided by an IReader object into the
loops database/the context object. Will typically be used as an adapter.
"""
def load(elements):
""" Create the objects and relations specified by the ``elements``
argument given.
"""
class IWriter(Interface):
""" Transforms object information to an external storage.
"""
def write(elements):
""" Write the sequence of elements given in an external format.
"""
class IExtractor(Interface):
""" Extracts information from loops objects and provides them as
IElement objects. Will typically be used as an adapter on the
loops root object.
"""
def extract():
""" Creates and returns a sequence of IElement objects by scanning
the content of the context object.
"""
class ISubExtractor(IExtractor):
""" Used for extracting special informations from individual objects
that will be represented by sub-elements.
"""