cybertools/stateful/base.py

148 lines
4.8 KiB
Python

#
# Copyright (c) 2013 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 stateful objects and adapters.
"""
from persistent.interfaces import IPersistent
from persistent.mapping import PersistentMapping
from zope import component
from zope.component import adapts
try:
from zope.component.interfaces import ObjectEvent
except ImportError: # Zope 2.9
from zope.app.event.objectevent import ObjectEvent
from zope.event import notify
from zope.interface import implements
from cybertools.stateful.definition import statesDefinitions
from cybertools.stateful.interfaces import IStateful, IStatefulIndexInfo
from cybertools.stateful.interfaces import ITransitionEvent
class Stateful(object):
implements(IStateful)
statesDefinition = 'default'
state = None
def getState(self):
if self.state is None:
self.state = self.getStatesDefinition().initialState
return self.state
def getStateObject(self):
states = self.getStatesDefinition().states
if self.state not in states:
self.state = self.getStatesDefinition().initialState
return states[self.state]
def doTransition(self, transition, historyInfo=None):
sd = self.getStatesDefinition()
previousState = self.getState()
if isinstance(transition, basestring):
sd.doTransitionFor(self, transition)
self.notify(transition, previousState)
return
available = [t.name for t in sd.getAvailableTransitionsFor(self)]
for tr in transition:
if tr in available:
sd.doTransitionFor(self, tr)
self.notify(tr, previousState)
return
raise ValueError("None of the transitions '%s' is available for state '%s'."
% (repr(transition), self.getState()))
def getAvailableTransitions(self):
sd = self.getStatesDefinition()
return sd.getAvailableTransitionsFor(self)
def getAvailableTransitionsForUser(self):
return self.getAvailableTransitions()
def getStatesDefinition(self):
return statesDefinitions.get(self.statesDefinition, None)
def getActors(self):
return None
def notify(self, transition, previousState):
""" To be implemented by subclass.
"""
class StatefulAdapter(Stateful):
""" An adapter for persistent objects to make them stateful.
"""
adapts(IPersistent)
statesAttributeName = '__stateful_states__'
request = None
def __init__(self, context):
self.context = context
self.msgFactory = self.getStatesDefinition().msgFactory
def getState(self):
statesAttr = getattr(self.context, self.statesAttributeName, {})
return statesAttr.get(self.statesDefinition,
self.getStatesDefinition().initialState)
def setState(self, value):
statesAttr = getattr(self.context, self.statesAttributeName, None)
if statesAttr is None:
statesAttr = PersistentMapping()
setattr(self.context, self.statesAttributeName, statesAttr)
statesAttr[self.statesDefinition] = value
state = property(getState, setState)
def notify(self, transition, previousState):
transObject = self.getStatesDefinition().transitions[transition]
notify(TransitionEvent(self.context, transObject, previousState, self.request))
class IndexInfo(object):
implements(IStatefulIndexInfo)
availableStatesDefinitions = [] # to be overwritten by subclass!
def __init__(self, context):
self.context = context
@property
def tokens(self):
for std in self.availableStatesDefinitions:
stf = component.getAdapter(self.context, IStateful, name=std)
yield ':'.join((std, stf.state))
# event
class TransitionEvent(ObjectEvent):
implements(ITransitionEvent)
def __init__(self, obj, transition, previousState, request=None):
super(TransitionEvent, self).__init__(obj)
self.transition = transition
self.previousState = previousState
self.request = request