cybertools/meta/config.py
helmutm a9cf186875 make configuration queries more fault-tolerant
git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@3574 fd906abe-77d9-0310-91a1-e0d9ade77398
2009-10-12 06:04:17 +00:00

91 lines
2.7 KiB
Python

#
# Copyright (c) 2009 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
#
"""
Basic implementations for configuration options
$Id$
"""
import os
from zope.interface import implements
from cybertools.meta.element import Element
from cybertools.meta.interfaces import IOptions, IConfigurator
from cybertools.meta.namespace import AutoNamespace, Executor, ExecutionError
class Options(AutoNamespace):
implements(IOptions)
def __call__(self, key, default=None):
value = self
for part in key.split('.'):
value = getattr(value, part, None)
if isinstance(value, Element):
value = default
return value
class GlobalOptions(Options):
_filename = None
_lastChange = None
def __call__(self, key, default=None):
if self._filename is not None:
fn = self._filename
if os.path.exists(fn):
modified = os.path.getmtime(fn)
if self._lastChange is None or self._lastChange < modified:
Configurator(self).load(file=fn)
self._lastChange = modified
return super(GlobalOptions, self).__call__(key, default)
class Configurator(object):
implements(IConfigurator)
def __init__(self, context):
self.context = context
def load(self, text=None, file=None):
if file is not None:
if hasattr(file, 'read'):
text = file.read()
else: # must be a file name
f = open(file, 'r')
text = f.read()
f.close()
result = Executor(self.context).execute(text)
if result:
raise ExecutionError('\n' + result)
def dump(self, file=None):
text = str(options)
if file is not None:
if hasattr(file, 'write'):
file.write(text)
else: # must be a file name
f = open(file, 'w')
f.write(text)
f.close()
return text