cybertools/stateful/definition.py
helmutm 154f2dcead minor modifictaions and extensions for the tum.sm project
git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@1936 fd906abe-77d9-0310-91a1-e0d9ade77398
2007-08-20 10:03:32 +00:00

105 lines
3.2 KiB
Python

#
# Copyright (c) 2007 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
#
"""
State definition implementation.
$Id$
"""
from zope.interface import implements
from cybertools.util.jeep import Jeep
from cybertools.stateful.interfaces import IState, ITransition
from cybertools.stateful.interfaces import IStatesDefinition
class State(object):
implements(IState)
def __init__(self, name, title, transitions, **kw):
self.name = self.__name__ = name
self.title = title
self.transitions = transitions
for k, v in kw.items():
setattr(self, k, v)
class Transition(object):
implements(ITransition)
def __init__(self, name, title, targetState, **kw):
self.name = self.__name__ = name
self.title = title
self.targetState = targetState
for k, v in kw.items():
setattr(self, k, v)
class StatesDefinition(object):
implements(IStatesDefinition)
initialState = 'started'
def __init__(self, name, *details, **kw):
self.name = self.__name__ = name
self.states = Jeep()
self.transitions = Jeep()
for d in details:
if ITransition.providedBy(d):
self.transitions.append(d)
elif IState.providedBy(d):
self.states.append(d)
else:
raise TypeError('Only states or transitions are allowed here, '
'got %s instead.' % repr(d))
for k, v in kw.items():
setattr(self, k, v)
def doTransitionFor(self, obj, transition):
if transition not in self.transitions:
raise ValueError('Transition %s is not available.' % transition)
if transition not in [t.name for t in self.getAvailableTransitionsFor(obj)]:
raise ValueError("Transition '%s' is not reachable from state '%s'."
% (transition, obj.getState()))
obj.state = self.transitions[transition].targetState
def getAvailableTransitionsFor(self, obj):
state = obj.getState()
return [self.transitions[t] for t in self.states[state].transitions]
# dummy default states definition
defaultSD = StatesDefinition('default',
State('started', 'Started', ('finish',)),
State('finished', 'Finished', ()),
Transition('finish', 'Finish', 'finished'),
)
# states definitions registry
statesDefinitions = dict()
def registerStatesDefinition(definition):
statesDefinitions[definition.name] = definition
registerStatesDefinition(defaultSD)