class StatefulSubject(Subject, StatefulObject):
is_duck = False
is_pumpkin = False
initial_state = 'human'
state = StatefulObject.state # property
transitions = []
_workflow = None
@property
def workflow(self):
if not self._workflow:
self._workflow = Workflow()
for transition in self.transitions:
self._workflow.add_transition(transition)
return self._workflow
def test_workflow(self):
# create a workflow
workflow = Workflow()
assert len(workflow._transitions) == 0
# add an invalid transition
with self.assertRaises(AttributeError):
workflow.add_transition(object())
assert len(workflow._transitions) == 0
# add our "to_duck" transition to our workflow
to_duck = create_transition_to_duck()
workflow.add_transition(to_duck)
# create a stateful subject
subject = create_subject()
# check we can see our transition as available
available_transitions = workflow.get_available_transitions_for(subject)
assert available_transitions["to_duck"] == to_duck
assert len(available_transitions) == 1
# execute transition and check our subject is now a duck
to_duck(subject)
assert subject.is_duck
assert subject.state == "duck"
def workflow(self):
if not self._workflow:
self._workflow = Workflow()
for transition in self.transitions:
self._workflow.add_transition(transition)
return self._workflow
