8f96dca0a4
git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@1908 fd906abe-77d9-0310-91a1-e0d9ade77398
72 lines
2.2 KiB
Python
72 lines
2.2 KiB
Python
#
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# Copyright (c) 2007 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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Objects that defer attribute access.
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$Id$
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"""
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from twisted.internet import reactor
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from twisted.internet.defer import Deferred
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class Deferring(Deferred):
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def __init__(self, context):
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self.context = context
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Deferred.__init__(self)
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def __getattr__(self, attr):
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d = Deferring(self)
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reactor.callLater(0, d.getattr, self, attr)
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return d
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def __call__(self, *args, **kw):
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d = Deferring(None)
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reactor.callLater(0, d.call, self, *args, **kw)
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return d
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def __repr__(self):
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return '<Deferring on %s>' % repr(self.context)
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__str__ = __repr__
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def makeCallback(self, method, *args, **kw):
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#print '*** makeCallback', self, method, args, kw
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def cb(result, method=method, args=args, kw=kw):
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value = method(result, *args, **kw)
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#print '*** cb', self, result, method, args, kw, value
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self.callback(value)
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return cb
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def getattr(self, deferring, attr):
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ctx = deferring.context
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if isinstance(ctx, Deferring):
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ctx.addCallback(self.makeCallback(self.getattr, attr))
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else:
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value = getattr(deferring.context, attr)
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self.context = value
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self.callback(value)
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def call(self, deferring, *args, **kw):
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ctx = deferring.context
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value = ctx(*args, **kw)
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self.context = value
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self.callback(value)
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