Commit f1547f0d authored by Hanno Schlichting's avatar Hanno Schlichting

Removed `OFS.DefaultObservable` - an early predecessor of `zope.event`.

parent c724aba1
......@@ -44,6 +44,8 @@ Features Added
Restructuring
+++++++++++++
- Removed `OFS.DefaultObservable` - an early predecessor of `zope.event`.
- Removed `mime-types` option from `zope.conf`. You can use the `add_files`
API from `zope.contenttype` instead.
......
##############################################################################
#
# Copyright (c) 2002 Zope Foundation and Contributors.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################
"""Implement Observable interface (see
http://www.zope.org/Members/michel/Projects/Interfaces/ObserverAndNotification)
This class is intended to be used as a mixin (note that it doesn't
derive from any Zope persistence classes, for instance).
"""
from types import StringType
class DefaultObservable:
"""
See the Interfaces wiki for design notes:
http://www.zope.org/Members/michel/Projects/Interfaces/ObserverAndNotification
DefaultObservable is intended to be used as a mix-in, like so::
from OFS.SimpleItem import SimpleItem
from OFS.DefaultObservable import DefaultObservable
class Foo( SimpleItem, DefaultObservable ):
'''
Some foo or other
'''
...
def bar( self, ... ):
'''
'''
...
self.notify( "bar" )
Clients register with a Foo instance using the methods of the
Observable interface, e.g.::
foo.registerObserver( self.getPhysicalPath() + ( 'watchFoo',) )
When the Foo instance has its 'bar()' method called, it will
notify all registered observers, passing 'bar' as the event; in
this case, the client's 'watchFoo()' method will be called, with
the foo object and 'bar' passed as parameters.
"""
def __init__( self, debug=0 ):
self._observers = []
self._debug = debug
def _normalize( self, observer ):
# Assert that observer is a string or a sequence of strings.
if type( observer ) != StringType:
observer = '/'.join( observer)
return observer
#
# Observable interface methods.
#
def registerObserver( self, observer ):
normal = self._normalize( observer )
if self.restrictedTraverse( normal, None ):
self._observers.append( normal )
else:
raise NameError, observer
def unregisterObserver( self, observer ):
self._observers.remove( self._normalize( observer ) )
#
# Convenience method for derivatives.
#
def notify( self, event=None ):
bozos = []
for observer in self._observers:
obj = self.restrictedTraverse( observer, None )
if obj is not None:
try:
obj( self, event )
except:
bozos.append( observer ) # Veto not allowed!
if self._debug:
import traceback
traceback.print_exc()
else:
bozos.append( observer )
for bozo in bozos:
try: # avoid race condition if unregister() called before now
self._observers.remove( bozo )
except:
pass
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